Rowe Saturn Jukebox Amplifier problems

[amandandme197]

I have a rowe 61024903 amp for a Rowe Saturn Jukebo, and one side got all kinds of static and low volume along with blown fuses. I replaced the transistors with ST transistors, and replaced all the fuses. Hooked it back up, it made this weird astroids arcade game sound, blew 2 fuses on one side and both sides sound like garbage now. Anyone have ideas?

[Ken Layton]

I'm not familiar with the "Saturn" marketing name. What is the model number of the jukebox?

[ed12]

all rowe jukes used matched output pairs
if u replaced them with off the self replacements ? and did not re-bias the amp
guess what is gonna happen ??
also if it sounds like static..cap kit is in order
start from scartch..replace all transistor's,make sure the finals are a matched pair
re-cap,re-bias..carry on
a owners manual is handy right about now
as u need to :match: the rowe outputs to there :exact: spec

ed

[amandandme197]

Hey Ken, it is the 100i I believe. Ed, I am not electronicaly inclined and not certain of what you are saying (sorry) but I just replaced the transistors with the same transistor #s in the same numerical order they were. I put in new fuses, but do not know what the bias is, etc. I can't afford to get this repaired, and am trying to do it myself all from forum reading. I am lost. When I say static, i mean you can turn it up low, medium or full volume  and it sounds like the speakers are shot, but i checked them, and they are working fine. Also, the volume is very low at full volume. What it sounds like is what was explained in previous posts with transistor replacement, but that was all i did . I am capable of doing what needs to be done to get it fixed (i think) but I just don't know what to do, and or how to use a multimeter. If someone could help me out with the directions, I would greatly appreciate it. Thanks much guys.

[ed12]

i can walk u through biasing
but u will need a multi meter >digital i trust<
and the service manual..unless ken can chime in and tell me the bias voltage and resister to test across

ed

[amandandme197]

I have a non digital multimeter, but I have the manuals. Before I do this though, I need to get more transistors again, and fuses? Thanks

[ed12]

ok just ring me up when u are ready
make sure the outputs are matching..ie same beta/gain..etc
thats very important

ed

[lilshawn]

you basically need to have a pair of transistors that are matched very close. if one is different than the other it can cause a cascade effect that makes the transistors run away as they flip flop out of control till they blow up.

also, check the little circuit board on the underside of the heatsink with 2 diodes and 2 wires. they use it perform a temperature compensation. if there is a bad or broken solder joint on there it can cause the transistors to pop. about 90% of the boards i've checked have insufficient solder to hold the leads properly. the vibrations from the subs can cause it to break.

[amandandme197]

Will do ed. I will check lilshawn. I am using ST 2n6287 and ST 2n6284. I bought them from allied electronics online. What do i need to look for on the transistors besides the number? Thanks

[ed12]

thk-u lilshawn
i did forget that point in case

the transistors will have a suffix >mp<= matched pair
dose not matter if there both npn/npn  or pnp/pnp or a mix of the 2 pnp/npn
the suffiex must state >mp<

ed

[amandandme197]

Is there any wzy you could find them for sale on a site for me to purchase reasonably cheap? Thanks much

[ed12]

there is an op here that goes by the handle ami-guy
drop him a line :pm:
he may beable to help u.?
if not post the exact manual rowe #'s i will chk my manuals

ed

[amandandme197]

Will do, thanks so much.

[amandandme197]

Ok, in the parts manual I got this:
part no 70030206  Transistor (Darlington Amp, RCA-2N6284)(NPN, Q101, 2 places)
part no 70030207 Transistor (Darlington Amp, RCA- 2N6287)(PNP, Q102, 2 places)

[amandandme197]

Oh, i tried searching for ami-guy, armi-guy, army-guy, etc, and couldn't find anybody.

[ed12]

ami-man

my typo

>ami-guy<

ok so it is npn finals ? so both channels use npn ?
as outputs ?
please post me a picture of the final >output stage of the amp
so i can see it


ed

[Ken Layton]

Transistors can be purchased here:

http://www.cdadapter.com/repair.htm

Just scroll down to "Repair Parts".

Also here:

http://www.rowejukeboxrepair.com/

[amandandme197]

Thank you. Those look like the same number transistors i purchased first, just a different brand.

[ed12]

thank you very much ken.
go easy now the nick is  newbie to this..

ed

[amandandme197]

Ok, I am going to purchase those transistors, and hope they work. If they don't, I think I may put the amplifier in my backyard and use it for target practice.

[ami-man]

Hello amandandme197,

You do not leave your name or the country you live in, this is a world wide forum could you add the information to your profile.

If you are in the USA I would go with Kens advice and source the transistors from a reconised dealer such as he suggests or send the amplifier to Bruce Wentworth at A & B leisure to have it proffesionally refurbished.

If in Europe or the UK by mall means contact me for the same service.

Regards
Alan

Alan Hood
ami-man
UK

[amandandme197]

Im in the USA. I will go ahead and order the transistors. Thank you

[lilshawn]

2 x 2N6284
and
2x 2N6287

i would avoid e-bay... most of them are fakes. order from cdrepair.com, mouser, or digikey.

[ed12]

yes amandandme197
follow there advice..if u have never done this before.? it is wise to seek the help of ppl whom do it all day..
but that aside if u want to do it..ring me up i will guide best i can

ed

[ed12]

npn pnp so it is a push pull amp
u MUST chk the biasing  of these
and for the love of god make sure they are marked >mp<
or u will not get the bias right
aslo chk the diodes..

ed

[amandandme197]

Thanks ed. So the ones Ken listed are the right ones, right? They are MP? I will  have to do it myself Ed. Im broke. I have a 3 million transplant bill i am paying off, and meds that are over $5000 a month. This will have to be a do it yourselfer for me, and I will need help.  I really appreciate it

[ed12]

that's what we are here for is to help
sorry to hear about health issuies
but when u are ready i will get out my bag of toys
i am sure the other nicks will chime in also

ed

[amandandme197]

Thank you very much Ed. Health is better now due to the transplant and meds. Before i purchase,are those resistors ken listed mp?

[ed12]

i would have to think so
ken like me like a few other top knotch nicks here
do them all the time
and i have never found any problems with what he suggests

ed

[amandandme197]

  Nice, thank you buddy.

[amandandme197]

Hey ed, if you look at that second store Ken listed (Rowejukeboxrepair) or something like that, one transiztor is an mp and the other is not. The ones i installed, one is an mp, and one is not. I will take a pic

[ed12]

mp as i stated means matched pair..ie same spec's totaly 100%
so lets say beta on the pnp was 60% the npn must match it..
same with v-breakdown voltage ..lets say 100volts max on the npn..the pnp must match..same with gain..ihef lets just say 70% >gain factor< the pnp must match it..
hence the reason for matched pairs..or we just roll the dice and trough in any old pair,bais and hope for the best..

ed

[amandandme197]

Ok I see what your saying. There are 4 total, and as long as two on one channel match the two on the other channel the exact same.[/URL][/img][/URL][/URL][/img][/img]

[amandandme197]

[amandandme197]

[ed12]

after going through kens link

>"Rebuilt" 250 Watt Stereo Amplfier 61024903 /Exchange
You must first send in your exchange Amplifier 61024903 Once we receive it in, we will then send you out a "Rebuilt" replacement Amplifier the next day. The following >>"New Parts are included with each "Rebuilt" Amplifier that we do. 2 "New Driver boards. "New Pre-Amp board, 4 "New Output Transistors <<and much more. All "Rebuilt" replacement Amplifiers come with a 90-day <

follow the >> as what u need to do

also matched set means the npn and pnp of the same channel match

ed

[amandandme197]

all I can afford right now are the transistors. I cant afford all that other stuff right now or in the near future.

[ed12]

well my last post never made it up hmm
in your last pic..u can clearley see the word >mp< foward on 1 and reverse on the other..
as a rule they are sold as :pair's: for that exact reason..

now on the other parts..thats what we are here for to help u fix it cheaper then sending it in,so it may need a few diodes and caps,resiters..have at it
10% cheaper then sending it..and 100% better knowing u did it yourself
heres the trick..go slow and steady..listen up :alot: and carry on
rem u are the person doing the work. we are olny guiding u and are your personal sounding board until u have fixed..then its high 5's and we all go back to our corners

 ed

[amandandme197]

well my last post never made it up hmm
in your last pic..u can clearley see the word >mp< foward on 1 and reverse on the other..
as a rule they are sold as :pair's: for that exact reason..

now on the other parts..thats what we are here for to help u fix it cheaper then sending it in,so it may need a few diodes and caps,resiters..have at it
10% cheaper then sending it..and 100% better knowing u did it yourself
heres the trick..go slow and steady..listen up :alot: and carry on
rem u are the person doing the work. we are olny guiding u and are your personal sounding board until u have fixed..then its high 5's and we all go back to our corners

 ed

Awesome, thank you. I am going to start with Transistors to see if I can get it up and running, and then, slowly get the parts you posted. I will let you know when they come in. Is that ok, and do you think I still need to Bias the amp if I get those transistors from the guy Ken requested, or do you have to bias anytime you replace them?

[ed12]

as a rule u re-bias every time u replace an output
also do your self a fav do not put in the new 1's just yet
get them in by all means,but lets get a part list toghter here..
maybe ken can post us a link of the exact schmeatic ? so i can clearly see it
and stop talking out of my arse as it said..!!on the finer points!!..
u see it may need coupler caps,resisters etc..or as shawn said a pair of biasing diodes,plus rember to order new silcon :grease: and mica insulators for the output transistors,or all your work will be for not..
u see u go at this slowley but u will get there

ed

[lilshawn]

new insulators too. those metal cans CAN'T touch the metal AT ALL.

youll have to check the driver board too. they are the 4x4 inch boards on the back. sometimes some resistors burn out on there and some traces burn up. check them out and see if they look okay.

[ed12]

u c the rules for rebuild are comming in now
just keep in your mind we are here to help and not run u into the ground

ed

[amandandme197]

Sounds good Ed. Again, I can't thank you enough for taking your time and patience with me and my newbie  jukebox experience. I can play them, but fixing them is new to me. My fiance bought me it since I always wanted one, but was ever too sick to enjoy it. Now I am able to enjoy it, but just too poor to fix it.....But I guess it is a good thing I am still alive to fi it.

[amandandme197]

I thank you for that too

[ed12]

welp i am gonna save u a boat load of $$$ here
the new silcon i am refering to comes in about 4-5 sizes that i know of
get the 1 once size olny..that will be more then enough to do the job
the insulators are about 10 cents each..u need 4
plus if they came with what looks like white rings..they are actulay insulators also
alot of the time i salvage them from scrappers,but i do replace them also
resisters are about a dime each,caps rang but are cheap enough
i truly wish shawn or ken would hijack me and up-load a service manual..all i have is the rowe 100a cd manuals

ed

[amandandme197]

Well, I have  new insulators i pirchased with these last transistors that i never used due to salvaging the old ones. I have 3/4 tube of silcon grease left of a 1oz tube. I do not have the white rings, or transistors, etc.

[ed12]

as a rule when i go to a suppiler for the transistors all expect the grease comes in the pkg.
i know for a fact that if i buy ecg or nte >matched-pairs< the package states it
and comes with the full go..grease/mica's/insolaters :if used:?
some times the socket is made with the hole-throughs :chassic: instead of the white washer type insulater i am talking about..
so as long as u have grease and micas,u are good to go..

now do not just place these in when u get them..i want u to run some test's with me,what we do is bring the amp on with new fuses..and do some chks on the driver board's..i take it u do not have a scope.?...so i will need to go abit ol school
on these tests..do u have a spare audio reciever laying around ?..if so grab a pair of 1-4.7/mf-50 volt caps,we will want them to couple the amp stage's
this because we do not dc into the test reciever..at any time
we will problay go to phono input first >test reciever< then once we get to the finals we will go to line in..hence the reason 1mf and 4.7 mf
what we are duing in lue of a scope is coupling the sound out the amp..and doing some dc measurements on the way to see if there is other things wrong..as i supspect there is..so we want to nip it off in the butt
as shawn said >resisters< >burnt-traces< >cold solder joint's<
and i am looking for leaking caps..dc stuff right there
so even though this sounds like a pile of work..once u are done
u can high 5 and have at it

ed

[amandandme197]

Doing all that work is no problem, i am just happy you are helping me through it. I do not have a scope or a audio receiver though. What would be my next option? I think i may buy those transistors off the site  ken provided that come with two transistors, grease, and insulators. I will purchase that X2. I will not do anything with them once i get them and wait to  hear from you. What to do now without a scope or a receiver?

[ed12]

ok and good...we will save them new trannys till the end of this
no scope i kinda of took it as that..but no spare audio amp of any kind ?..most ppl
have something old laying around..rember i said we will go  ol school here
u do have a multi meter..that works in our favour..now rember i am not treding on u here..but do u know the scales and how to use them..? as that will be a lanuch point..rember without a scope and a spare reciever..i will need to dig deeper into my toy box.as it is said..but u have to answer me..another i need to know very badly..is do u own a soldering gun or a soldering iron ? as this will give me a better understanding,rember i am just setting the stage right now.so u do not wats your money,and get all pissie..i went through cardiac sugery 3yrs ago..so i know where u are comming from.glad u are better.. lets get this puppy fixed

ed

[amandandme197]

I do have a voltmeter/multimeter, but do not know what to set it on as it has numerous settings. I do have a soldering gun, and I have fixed many electronics in the past, but not to this extent. The voltmeter/multimeter has tons of settings, so I dont know where to start on using that. I know your not trying to beat me up, and just trying to figure out where I stand, what I have, and what I know. You are teaching me, and just asking questions you would need to know before we statt. Thank you very much ed. I have a bunch of transplant friends that are having failing organs, and going through cardiac surgeries, and they are no joke. Anything pertaining to the number one vital organ that keeps us alive and is under a rib cage is nothing that is fun. I am glad you are well too. It is funny how a lot of people have no patience for newbies, but this is how newbies learn. Everyone starts at the bottom, and works their way up. I am glad you have the patience. I really appreciate it. Are you in a US time zone, or are you in another country? Just tring to figure out the best time to work on this when we get going. Thanks again ed!

[lilshawn]

I don't have a digital version of the schematics. there was a site you could download them from, but they went to a pay site. should have scooped them while I could.

you don't need rings or anything on the screws. it's okay if they touch the metal can. they screw into the phenolic holder base that the transistor clips into so they remain insulated. you just have to make sure you don't have the shaft of the screw touching the side of the hole in the heat sink.

the phenolic base has some ridges around the screw holes that are supposed to keep the base aligned with the screw in the middle of the hole so there is no chance of it touching, but it's easy to think they are seated properly when in fact it's not since it's view is obscured.

this holder also makes it so you don';t have to solder the transistors at all, you just unscrew them and pry them out. be aware though the base isn't attached to anything and you may have to disassemble the boards from the backside to reach in there and hold the base while you attach the new transistor.

protip: when you are finished installing the transistor test for a short with a meter between the can and the heatsink. if it's in the 100's or 1000's of ohms it's okay, if it's zero, something is touching somewhere and the can is grounded. You will need to fix it before you power it up or kablamo!

[Ken Layton]

We never had any "I" series jukeboxes on our route so I've never seen one. The highest Rowe CD juke model we bought was the "D" series. We had tons of "A" and "B" models though.

I understand that around the "F" model, Rowe changed the driver boards in the amplifier to "self-adjusting bias". There were no adjustment trimpots on those driver boards because they adjusted themselves.

In my experience over the years, any time the output transistors blew out again after being replaced, it was usually because there were additional bad components on one or both the driver boards. I have no experience with the new self adjusting driver boards, only the older driver boards with the trimpots on them.

Definitely all four of the output transistors must be electrically insulated from the chassis/heat sink so be sure all the insulating mica sheets are there and smeared with a film of silicone heat sink grease.

[ed12]

amandandme197
its ok thats what we are hear for
all i will need from  u at the moment is the model # of your meter
so i can snag its pdf,then i can easily guide u the rest of the way
i cut my teeth on anlog meters..so its an easy walk for me
ken and shawn thk-u for chimming in
i will ask ron over at phonoland for a copy
or maybe ami-man has 1 he could scan for me >amp-olny<
ken i truly hope this is a self biasing amp:)
would save us alot of time..
i am in canada eastern time  zone
but usally i am on off all day

ed

[lilshawn]

All the cd100 series machines used the same amplifier. I have dozens of manuals here... We don't leave them in the machines.

I had an issue with the new style self adjusting boards and new transistors. damn things sounded like they were blown when in fact they where good. i ended up switching out the boards with the sapre (i put the new boards in the old transistors amp and the old boards in the new transistor amp)  and had no problems with either one.  i don't know what or if they changed in the transistors in this particular run i got or how the new boards self adjust, but i'll be damned if i know what the deal was.

ANYWAYS...

for the old style driver boards, you have to check R21 R24 R33 and Q4. especially if the board looks like it got hot. R21 and R24 should be 180 ohms R33 should be 470 ohms. if r24 is toasty q4 is almost assuredly shorted.

i'll take the manual home with me today and scan the amp section into a PDF and post it here tonight when i have a few minutes.

[amandandme197]

Hey ed, it is a Sears ohm/voltmeter model# 982364

[ed12]

ya basic meter
but good enough for us
shawn said he might beable scan in a pdf for the amp
and away we go
i have my cd100 manuals i will look tonight
just got done a monitor overhaul..so me eyes are a tad slow
bear with me

ed

[amandandme197]

No problem ed, thank you. These are the transistors I bought and will probably buy again if they are the right ones due to the price, but do these look right to you? Thanks

http://www.alliedelec.com/search/productdetail.aspx?SKU=70013781] [url]http://www.alliedelec.com/search/productdetail.aspx?SKU=70013781[/url]
http://www.alliedelec.com/search/productdetail.aspx?SKU=70013779]  [url]http://www.alliedelec.com/search/productdetail.aspx?SKU=70013779[/url]

[ed12]

your links are broke ?
but no never mind..ken thk-u very much
it is truly a self baising unit
thk-u shawn for stating the diode chain i see it now
when shawn up-loads a scan ? i can explain why they have to be matched pairs and give u cleariatiy
u will be looking at the driver boards
as something is not right
it is a starnted push pull amp 1-npn 1-pnp per channel
4 self biasing per side >heat sink mounted>
the transistors are high gain darlingtons >best to have some sort of a load on them at all times,we normaly use a 100-125 watt light for this
u have 2 leds that will tell u if the amp is overload condition
u have 2 fuses pre driver board to deal with
u have 4 high power resisters per driver board
to deal with..again thk-u shawn for the heat issuie
we will need to adress these
now my manual is covering 61024901/q2-q2 d
mine has some voltages..but lists all parts values
so if shawn dose not chim in witha scan ?
i am on the road tommrow i will stop and get a good scan done

hope this helps

ed

[amandandme197]

Sounds good ed, thank you. 2 fuses on one board are blown.  The first four transistors I replaced (only one channel was bad but I replaced all the transistors anyway) were Motorola, so I assume they were replaced one time before. I dont know if that helps at all

[amandandme197]

You know, it also would not surprise me if the screws touch the heat sink. There is some play when putting them in. I may be wrong

[lilshawn]

here you go...if you want any other parts of the manual, let me know.

https://www.dropbox.com/s/lfz304hk6sxi0gp/saturn%20amp.pdf

[ed12]

before u buy anything le me chk into my grab bag of fools here
i may have a better source for them matched pairs
until then,u can remove the driver boards and inspect for problems
u must rember the heat issuie shawn spoke off
with them 5 watt resistors  your gonna get heat , trace lifting,cold solder joints
etc etc..what as a rule we normal do for good measure is :re-cap:..there old and will not be with in range anyways..
and for the cost it is like a investement
your meter is easy to use
it will fill your needs on this 1
expect for the low range resister  >5watt< jobs i see in parrall as they are .3 ohm and in parall that comes to .015ohm..your meter may not be up to the snuff there
but again they are cheap enough >side on the favor of no error here<,
with the driver boards cleared up,we can move on to testing >with out the finals in<
for our proper voltages..if they are there and good..we can lock in the finals and give er a go..light load olny >150watt bulb<..i say that because i do not like snapping my drivers with a hudge dc thump..
so i always use a light bulb
now onto your meter
u will have what we call a range switch to switch between different ranges
so
dc-volts 2,20,200/ac volts 2,20,200 much like that
then u will have what is called a ohm scale 1k/10k/100k/1meg much like that
when we do dc voltages it is always refered to ground >chassic< unless i tell u different,if so i will spec where to place the probes
red will always be your + lead/ black will always be your ground lead
again unless i explain to u different
for resisters i will tell u what scale to go to,and u will place the probes >across< the resister in question..caps u cannot test right with that meter hence why u are doing a little shopping list to recap the unit..there is just no way with what u have that we can get the readings we are looking for..
for diodes u will go to your lowest ohm scale 2ohms for the sake of it
if u read 2ohms your meter will go all the way from left to right
that makes it a 2 ohm resistor
for a diode if u measure it 1 way and the meter dose not move u will reverse the probes and test it again,what u just looked for was a shorted diode or leaky..leaky can be a tad tricky on an anlog meter but we can get thourgh it
now a hint hear
if u go to ohms range :any: scale and short the probes the meter will deflect from left to right..dead short..

thk-u shawn
ed

[ed12]

in light of the doubt
remove heat sink
remove sockets..they will come out
inspect for broken insulater on the hole throughs
if u fig they may have done it error on the side of cutting wood
double measure twice cut once

ed

[ed12]

i just went through the pdf
shawns shows a biasing control on the diode board where mine dose not
we had better nail this amp rev down..
please chk that board for a control >biaising board on the heat sink<
there will be 2 if there there

ed

[amandandme197]

Oh boy.........

[amandandme197]

How do you connect a bulb, or know what looks bad,........my head is spining

[lilshawn]

How do you connect a bulb, or know what looks bad,........my head is spining

yeah ed's kind short and to the pint.

he basically says take a look at your driver boards and let him know which ones you have (the schematics i posted are 2 different kinds and part numbers.) let him know which you have. like we mentioned before, there where 2 different kinds of driver boards, an older one where you had to manually set the transistor bias by adjusting a trim pot, and a newer revision that did this adjustment automatically. (no adjustment necessary)

also to inspect the board for signs of burning hot parts. check the traces for lifting broken solder etc. darkening of the board.

test the resistors. you can look up the part designations and see what they are supposed to be and compare them to what you read. all values should be within about 5% (for example a 420 ohm resistor should be between 399 and 441 ohms)

resistors start reading higher and higher if they are beginning to fail or have been hot. and may read 100's or 1000's of ohms higher than it's supposed to.

[amandandme197]

Got ya shawn, thanks. I do know that the two smaller boards have two fuses each with one above the other, and each board has 3 red led's on it with two being close to each other, and the other more in the middle of the board.....if that helps. Also, how do i take these things out without cracking the boards, as the two smaller boards are plugged into the huge board.

[ami-man]

Hello amandandme197,

To take out the boards out of the chassis, remove the jumper plug on pre-amplifier and press on each of the pawls of the plasic clips that hold the pre-amplifier in place one at a time in order to lift the board at each point.
Remove the plug that goes to the mute connection on the board.

With regards to cold joints look at the pins on the jumper plug for any cracks on the solder around them, if there is a sign of cracking you will have to resolder the connection, do the same on the two connectors that go onto the pins from the driver boards.

As stated before now remove the driver boards the with the same method as above and check all of the pins again for cold joints and resolder if required.

Whilst you have the diver boards out of the chassis, look at the larger 2 & 5 watt resistors on the boards for any over heating or cracking of the surface coating, if that is the case then they will need to be replaced, some of these resistors can be very low impedance that has to be the correct value, also check that the solder joints on these resitors is good.

As already said make sure that the transistors that you have replaced previously are in the correct location and are insulated with the mica/plastic insulator that has the heat compound on it and that the fixing screws are tight in order to make the collector connection on each transistor.

For testing purposes I would fit a slightly smaller fuse to help protect the new transistors, a 5 amp should be ok without a load on the amp.

If the transistors or the resistors get hot staight away or if the 5 amp fuses blow then you have major problems that I fear are beyond your scope.

Regards
Alan

Alan Hood
ami-man
UK 

[amandandme197]

Ami Man, Thank you. I am still looking but don't see much. This is what I have. If anyone sees anything, please let me know. All solder joints look good.



http://www3.picturepush.com/photo/a/13798956/img/13798956.jpg[/img]

[ed12]

correct me here
but that looks like a self biasing  unit to me
refer to the pc in the middle of the heat sink

the resistors we are talking about are the 1's that look like big bricks
they look good
the boards look fine..no damage i can see

what we do now is some tests with that meter of yours..

also u may have either shorted out the outpus placing in the new 1's
and or forgot to do a few steps.? refer back to replys here
or your speakers are shorted and or the out put tramsormer..?

this is what the light test is for in its cleartly..so we can see load without the outputs
in...

ed

[amandandme197]

Ok ed, I have no parts and no spare fuse (they have not came yet). Can it still be tested, and how do i hook up that light? Thanks

[lilshawn]

yes those are the auto bias boards. 40710105.

no adjusting for you! 

the manual bias adjust driver boards are 40710104

you may still run into the issue where they "sound" blown like i did with those boards.

we will cross that bridge if it comes to it.

[amandandme197]

Nice. Sounds good. 

[ed12]

ok light test..
as long as your fuses are ok.?,chk them for NOT OPEN STATE,as per my meter refernce below,lowest ohms,see which the meter moves when u short the probes.
this is exactley want u want when u measure on either side of the fuse..
in short 1 probe on 1 end of fuse,other probe on other end..
meter must deflect all the way..i tend to lift 1 end of the fuse out,so i know i am olny probing >looking< at the fuse olny..

now on to light test..get any 40/60/100 watt house hold light bulb
solder 1 wire to the outside ring
solder 1 wire to the bottom center of the bulb
boom u got a light load..
a 40 watt for what we are doing is fine..but as your bugdet is small
any size just spec it to me so i can deduce what i will expect
WE WIIL NOT HAVE YOUR FNALS IN AT THIS TIME >FINALS=OUTPUTS<
first we will make sure your fuses are good..not by looking at them but rather by using your meter
we move on from there

ed

[amandandme197]

Got ya, sounds good. 2 fuses are for sure bad as the wires inside are melted in to two peices. I will  have to order some fuses for sure.

[ed12]

now that is where a few light bulbs wired exactley as i stated come in handy dandy
as u can wire in the bulb >jump< the fuse,and test along.....
now u know why i want light bulbs....
by now u should understand it

ed

[amandandme197]

Ahhhhh, so as long as I am using the lightbulb to test the amp, i can use foil to jump the fusees that are bad, or use another lightbulb wired up as a fuse? I am assuming you mean jump the fuse with foil.....

[ed12]

never never ever with foil or a soild piece or wire
that is is a very very bad no no
the bulb will persent a 4-8 ohm load
this is ok for testing
much like a fuse but not the same
were a fuse will :snap: foil will not/nor a piece of wire..in the trade we call that a crowbar,the bulb will either light or be drak or be some what lite,or will strobe
we want that....
full light means no load >good but we can test more<
full dark means full load>bad we need to stop right now<
strobe means passing audio>what we are looking for<
it is the easy way to save a few dollars and alot of fuses

ed

[amandandme197]

Ok, got ya. So the bulb will nut be used on the speaker outputs, but instead the fuse holders, and if so, beings there are two fuses per board, do i need 2 bulbs per board. Im catching on, but I skjust dont want to screw it up.

[ed12]

at this point the speaker outputs are a mute point..
as they olny come into play once where have chked the driver boards
and made sure they are ok...
we are olny going to jump in the 2 bulbs to do exactely as i said
they will act as a fuse in a out side manor..this means we can tell
what is going on after the :fuses:,before we replace the fuses with new fuses
that will save u some time and $$$$
this is a normal bench test for any tech,bench tech
i do it on the road..i can tell from the light what is going on :down-stream:=load
once i am happy..i will replace the fuses..carry on
for u 2 equal lights25/40/60 <best> 60 or 100 watt
u can then test away with about 80% know u will not blow any down stream up
by keeping an eye on the light..
simple but works,>ol-school<

ed

[amandandme197]

That is awesome! Ok,So should I go ahead and put this thing back together for to be ready for the next step?

[ed12]

once we do a few chks with the meter
then by all means yes
until then keep both driver boards out..
it is to late for me tonight to go any futher
but u are about to get another lesson about your meter

ed

[amandandme197]

Ok, no problem ed. Thanks again. Sorry if it seems as if I am not grasping it, I just want to make sure what I do is right. I dont want to screw it up because of my own stupidiy.

[amandandme197]

Ed, Shawn and Ken, I appreciate all of your help. If it were not for people like you guys, us newbies would not have a leg to stand on. Everybody learns some time, andI just happen to be a late learner and you guys are teaching me. Thank you for your time and patience.

[lilshawn]

the light bulb would be used in place of the fuse. it's going to act as a current limiter.

basically you jump the burned out fuse with the bulb filament. when the bulb is inserted in the fuse holder, instead of a fuse that would burn out right away, the lightbulb lights up. the brighter the light, the more current that is flowing.

from this, you can deduce...

A) something is shorted out because the lightbulb comes on really bright.

B) something is open because the lightbulb doesn't come on at all.

c) nothing is wrong because the bulb comes on dim (or at least not as bright as it would be if it was shorted)

[ed12]

lilshawn
thk-u very much
i thought i had it a tad backwards
but the point is the same
lets get to these  drivers
and by all means please..correct me as i go

ed

[amandandme197]

Ook, so do you think i need to order more trans, or do you think there may be a chance i didnt blow my new ones?

[ed12]

at this point we are going to save our money
and do a few tests incase u need more then just the finals
i suggest u get the light bypass made up
and tell me the size of bulb u are going to use
etc etc

ed

[amandandme197]

Sounds good buddy, I will work on that today.

[amandandme197]

Never realized how hard it is to solder wires on a rolling light  bulb. Finally used a drinking glass to hold it and all is done.

[ed12]

congrads
u have 2 bulbs right ?
and what are there wattage..>important for me to know<
this way i can do the math..

ed

[amandandme197]

Thank you sir. Yes, two bulbs, 60watts each.

[ed12]

60 watts is great
easy math
let me unload my service stuff
and i will get out the manual and start u on using your meter to chk the driver transistors,easy enough to do :once u get the hang of it:,
then we chk the usual stuff,resisters and such..even though i do not think your meter will give what i want from the 5 watters,what is that saying nothing venered nothing gained...
will get back to in a byte or 3

ed

[amandandme197]

Awesome, sounds good.

[ed12]

ok on the driver board find q4 and q7..set your meter to the lowest ohms scale
short there probes togother to make sure your meter deflects all the other way
get back to me..in my manual it olny shows the right channel..so i will have to asume
that the left driver board will be listed the same
we start there..find them transistors first..they are the driver transistors


ed

[amandandme197]

Ok, getting ready to put my little one to bed, and i will be right back

[amandandme197]

Ok ed, I put it on RX1 and it topped ouf like you said. Ready to go. I will check those and let you know

[amandandme197]

Bothe boards q4 and q7 seem to be reading 5 ohms

[amandandme197]

What is the ohms adjustment dial next to the voltage switch need to be at. All the way up or down?

[ed12]

for the moment the lowest
so if 100 is the lowest.? then that is the 1 we use
if it is 10 then that is the 1 we use
u see the :range-switch: sets the max value
so lets say 10k is a range..and u place a 10k resister across the porbes
it should read 10k or very colse give or take 5%/10% etc
so if 100 ohm is the lowest then the same applys
with the driver at first we want to use the lowest range
all we are going to do is to see if we have a short--/b-c/b-e/e-c
simple tests
then we will change range a tad to make sure we are not :leaking:,if not we can deduce that the drivers are good,we then move on to the diodes using the same method..1 range then another..
if all chks out good
then will place in our lights as fuse's >loads<
and do some vcc chks
on your meter this will be >dc<
range here same applys  but we tweak the range, but that comes after we do some simple transistor chks

ed

[amandandme197]

Ok, all read good except both q4's  e&c read very low

[ed12]

ok thats a pnp
can u remove them without hurting the transistor or the board.?
plus u did not do the reverse chk yet..but that is ok..
if u can remove them we go from there
i almost want to have u pm me your phone # so i can call u
but as i want the public to know this..i cannot type and explain at the same time.
and there is nothing across e-c that should cause that ?
if u can remove them do so..we will double chk

ed

[amandandme197]

So completely unsolder them?

[ed12]

at least 2 legs yes
make sure the legs are free
go easy....solder wick or a solder sucker is handy right now

ed

[amandandme197]

Well, you want me to remove them completely, right.?

[amandandme197]

Actually have to get off here ed, but if you want, we can complete tomorrow.          I will pm my phone number if that may help you. Thanks buddy

[ed12]

if it is easier for u to complety remove them?
then by all means yes,1 at a time,once have chked it u put it back in then move on to the next 1,we are getting somewhere now

ed

[amandandme197]

OK, I dug out a soldering iron and a solder sucker out of my old bag of electronics tools and devices. Trans is unsoldered.

[ed12]

ok good to hear
man that puts a smile on the face
now u have 3 legs
base=b
collector=c
emitor=e
we will go to low ohms rx10
and we will go black to b red to c we will look for full meter movement
if we get that the tansistor is bad
we then do the same b to e
we the reverse the probes
red to b
black to c
then to e
what we are trying to find is if we have a :shorted transistor:
foward breakdown voltage is .5v so we may need to jump up 1 knotch on the ohm scale.?
but we will cross that bridge soon enough
long way for us to go..but u will do this for each of the drivers
4 in total
as u remove it 1 of 4 and are happey with it place it back in
then go to the next 1
i will dig out a analog multi in the afternoon and go hand to hand with u
just finishing up some power supplys tonight
so i really can not go alot futher
maybe shawn can chime in ?

ed

[amandandme197]

Sounds good buddy. I will see what I get. Thanks again, and talk to you soon.

[ed12]

here this should help clear up some of the mud

>http://www.elexp.com/t_test.htm<
read it complete
print if u can for refernce
u will get a darn good idea,the rest is a cake walk

ed

[amandandme197]

Will do. Thank you sir!

[amandandme197]

Ok, all looks to be ok and is soldered back to the board.

[ed12]

ok great news..
now we move on the same way
make sure u do all 4 of them >drivers<
then we will chk some diodes >easy as hell as we olny lift 1 lead<
if all chks out good? we move on to phase 2..:lights:,if that turns out good
we spend our money on the finals..and fuses..
like i said 1 step at a time..take your time,i will be here for ya..
hope that guide worked for you ?

ed

[amandandme197]

Awesome ed. Yes, it helped a lot, thank you. What diods need checking

[ed12]

hi
i went over shawns pdf..the olny real thing they did change from what i can see
is they went to self biaisng..so that pdf is very very revelent in our case
so snag it please..the self biaising diodes i will spec for u,but all diodes in the driver chain need to be chked..
if all is good  move on to the first light test..where we chk vcc and -vcc
then we order parts
and repair amp
glad that link worked for u >

ed

[amandandme197]

Sounds good ed, i will check it out. I may need your help with the light test. Thanks again buddy.

[ed12]

light test is easy...
we will put the lights in place of the fuses..
then we will pre test the amp >without finals<
we will then chk vcc ranges to make sure they are with in range
if all chks out.?
we order what we now know we need
and do a final test with the lights to save our spearkers
fuses are cheaper..
we then put our speakers to it..enjoy our music and high 5's

ed

[amandandme197]

Hey ed, is there some way you could send me that download shawn put up. My device will not download it or open it at all for some reason. I think it is my tablet.

[lilshawn]

yeah, sorry i had to upload it to dropbox because the forum has a 2mb limit for attachments. the file ended up being 6mb. if i squashed it down to under 2mb, you couldn't see anything it was so blurry and pixely.  egh you do what you can.

[amandandme197]

Got ya. No problem. Thanks any way Shawn.

[ed12]

i will put a .txt toghter for u
and get it up here

ed

[amandandme197]

Again, thank you ed! 

[ed12]

sorry this took so long
but as i feel like a bag of crap
and been searching for some fets to finish off another power supply,well time got away from me
the txt applys to both channels
u must do foward and reverse tests as out lined in the link i posted for u
watch the 5.1v zeners

ed

[amandandme197]

I appreciate it buddy. Will read it now

[ed12]

how u making out bud ?
was that info good enough or do u need more
just let me know

ed

[amandandme197]

Hey ed, I will have to use our pc to view it. Iwas not able to do it last night or today due to Halloween and taking our daughter oht to get candy. I will look at it tomorrow though for sure, and let you know. Thanks buddy!

[amandandme197]

   I am so lost tonight. What should these read on the ohms scale? Thanks Ed


diodes used in rowe amp setcion driver board

cr1 diode silcon  normal readings
cr2 diode silcon  normal readings
cr3 zener diode 5.1 volt
cr4 zener diode 5.1 volt
cr5 zener diode 10 volt
cr6-cr13 diode silcon nornmal readings
they as follows
on your lowest scale forward should give u a # reverse should read open

[ed12]

on the lowest scale 1 way  they should deflect the meter all the way
on the lowest scale the other way meter should not move
now..if it dose go up 1 range  ie 1x-10x
break down foward voltage of a normal silcon diode is about .5v
your anlalog meter will at rx-1 present about .75-1v so i tend to go a range up
the zeners on the other hand are a tad testie to test with analog
can be done however..done it did it have a tie shirt for it
rx100 is the best range for zeners..then work backwards
ie rx100-rx10-rx1
normal silcon rx1-rx10

ed

[amandandme197]

Ahhhhh got ya buddy. Thank you. Had a rough day, so im not thinking too straight. Thanks again buddy

[ed12]

take your time...
i am going no where...thats a period..i got your back

ed

[amandandme197]

Thank you buddy. I will be up front with you and let you know math was never my strong point, so I may need some help when i do this. I really want to get this thing up and going so bad.

[lilshawn]

this would be a really good time to buy yourself a digital multimeter. they can be had for next to nothing these days. it makes things super quick and easy. I'm not saying spend $500 bucks buying a top of the line Fluke meter, but certainly (like everything else these days) the more you spend, the better they get.

basically, make sure it has a diode test function on it and a "continuity beeper". makes testing super easy.

"autoranging" is more expensive, (probably in the 50+ range) but worth it if you have no clue about circuits. just choose AC or DC on the meter and plunk the leads on the circuit, the meter auto adjusts and displays the voltage. same with resistance, plunk it on and bam! 15k ohms or whatever...no need to set the proper range or anything.

meter that seems good to me:

http://www.radioshack.com/product/index.jsp?productId=20362256#

[ed12]

oh shawn u could not have been any righter
but as i know the nick has little funds left over..we have but 1 choice ol school
let me get out my rat shack analog meter today
and we can walk hand in hand on the diodes

ed

[ed12]

ok first step
take out your meter
and short the 2 probes toghter,find the zero out ohms control
your meter will deflect all the way to the right with the probes shorted
and the end of the scale u can see a 0..with the probes shorted this is where u :dial in the zero ohms contorl to:,u might have to do this for each range on the ohms scale.,now with that in hand go to your lowest scale rx1 or rx10
and chk the silcion diodes >not the zeners<
just cr1,cr2,cr6-13..foward should give u a reading of about 5,reverse is open
foward is where u place the red+ probe on the band or chatrode end of the diode
black  goes to the orthe end
reverse is what it means
then the guide ^^^ applys
this is for your silcion diodes :olny:
chk them first,i will post u on the zeners

ed

[ed12]

ok now onto your zeners
they will foward read the same about 4-8 ohms
reverse should get a reading of about 150-100 ohms
that means they are good,any other reading means bad and must be replaced
zeners are a tesstie lot..they will test good out of circuit but break-down under load
hence the reason most re-builders just replace them..i mean the cost is so low why even fudge with them ?
now if the silcon diodes chk good and the zeners also
make sure everthing is soldered back in tight like and clean
put in your 2 lights into the fuse spots and we test +vcc and -vcc
to make sure we are good..if this happens right ? we then order the new :matched-pair: outputs pre side,and fuses
and some silcon grease..and :mica's: DO NOT USE THE OLD 1'S
there is alot of reason for not..and i know people will aruge with me..
but i dont give a dam..proper service means just that..
and your amp should be ready to give u sound again....
let me know when u want to do the vcc chks
i will guide u

ed

[amandandme197]

I did find only 2 of the same exact meters on ebay for $29 and free S&H. I will see if the wife will let me do it. I doubt it, but I will ask. Thank you ed! In the meantime  i will go with what you said ed,  and see how i do. Thank you guys 

[ed12]

if u want to go digital great..makes life simple
but the readings i gave u today are off of a analog meter
resister ranges
x1/x100/x1000
so it is your call
now  if all is right with the diodes we will be moving to volts
thats a whole new animal to use with an analog meter
but the rule is still the same

analog was here first..digital came later..i can be held to account for my digital use
but none the less i have my handy analogs

btw a side note here..any used meter u should ask the person to go to ohms
and short the probes..it had better read 0
if not run away

ed

[amandandme197]

Sounds good ed. These two on ebay are brand new. My wife said go ahead, but with that "not  really" tone of voice.....lol. I think it would be better for both of us ed. I am debating. I just need a go ahead, and ball is in my court, not saying I will get a chewing, but it will be easier in the long run. I probably will never use it again, but who knows. 

[ed12]

welp go ahead..i do it all the time
wiffie will look at me and say..u made xxxxxx this week why do u olny have  xxxx ?
i take her by the hand and show her something she will never know how to use let alone get rid of if i pass...but hey wtf right
go for it...u will use it again and again and again
when u do work around the house..gloat and say let me go get my digital meter
that will shut er up

ed

[amandandme197]

Laughing ---my bottom--- off ed!  I probably will, but that puts me $60 in to this so far with the transistors i bouhgt, compound, and insulators. I still need fuses, and who knows if the new transistors  are bad now. Im going nuts. If it was not for you guys it would be in my yard filled with led.

[ed12]

on your output pairs
i am sorry to say there is no iron clad test for them..
reason is as follows
they are high gain darlington with internal resisters
nasty to deal with when u never have..its a 50/50 crap shoot at best..even for me,
i need to read the specs about 3 times..rem i have been at this 45 years..
b-c b-e foward and backwards can and will confuse the fudge out of u.
unless of course it is a dead short.?
from there u need another type of meter to test them critters with..and it costs about 200.00..why do that when replaceing them is about 25.00 each side..
see my point?..that 200.00 meter u olny use in a repair shop..
much like back in the tube days when your b/w-color tv died and dad would go to the drug store to use that :special machine: to find the bad tube-'s,and pay for the new 1's well u had a soda. .25 cents,unless u are going to take up electronic repair
as a living..i would go the easy route..not to discourage u..but to guide u
a penny saved is a penny earned

ed

[amandandme197]

I got ya ed.

[ed12]

ok all the fun aside lets get back on track
i posted how to test the diodes..both types
then i posted if they chk ok.?. lets get these driver boards back toghter..so we can test a few voltages..this way we know where we are going to spend our $$$
your digital meter will come in very handy for you..later..but for now we are ol-school,unless u want to wait ?.if so okie dokie..keep in mind i have a new type of micro i am going to test on merit's and pga golf game's..it is linux and takes a boat load of re-learning some code and porting..the micro is a rasberry pi..it should work perfect for what our trade need's..but once i get to the :key: issuie: i will be pouring over code..which takes a boat load of mental work for me..
and as i want to pick up my test units first of next week..and have it all ported by feb
2014..thats a boat load of work..lets use the test i showed u..and get these critters ready to run...

ed

[amandandme197]

Ok ed, got ya. Starting on it right now. It is 2:15pm est Sunday.. thanks buddy

[amandandme197]

 :cheers:Hey ed, my driver boards do not have any cr diodes. I have the other style driver boards 40710105 so would I do the d1, d2, etc?

[ed12]

ya same syntex  cr1=d1 etc
its like where u see a resister makred .1kohm..u go wtf
that is 100 ohms
cr stands for current recifiter d stands for diode
both mean the same thing
expect for zeners which will as a rule have a :board mask: with a symbol
that looks like >z< which donates zener
others will have a board mask with >|< which means normal diode recifter
and donates chathode and anode :polairty:

ed

[amandandme197]

It seems like everything is ok. That is weird. What would make this thing stop working?

[lilshawn]

usually amps blow because they have been improperly loaded with speakers or there is an electrical fault.

you need to maintain a certain load on the transistors otherwise they go pop.

you can hook 100 speakers up to an amplifier, as long as you maintain the correct load. if you start daisy chaining speakers on there, the load gets less and less and less until it's basically a dead short across the amp transistor.

[amandandme197]

Everything on it is still factory buddy. I mess with nothing unless it is broke or I know what the ohms can be dropped down to and be stable at the same time. This amp I had no clue, and the speakers on the juke were plentu sufficient. I used to hook up car stereo systems, so I am pretty familiar with not overworking an amp, but this one was never touched. Could it be age maybe, or do you think something else shawn since the transistors I removed were motorola and not the originals?

[amandandme197]

Meaning I dont think the transistors were 20 years old

[ed12]

just what shawn said.or ??

It seems like everything is ok. That is weird. What would make this thing stop working?

this is not our point here..our point to make a effective repair
we can look into the what ifs later
if u follow what we have been saying..and do it the tried and true way..
once we are running u can go ok why..but we are not there yet
this comes :after: the finals are in place and we :light-load-test-it:,
then we ok do i have blown speakers ? blown output transformer ?
did a previous person put in un-matched outputs ? or run in un-proper loads ?
was the amp fourced to run at full power under adverse loads :ie: 2ohms or 32 ohms
the q's are long,and without knowing the full history of the box involved..
it is best to effect a proper repair and then once tested on the :lamp-load:
we do a few other chks using your meter..

ed

[amandandme197]

I got ya

[amandandme197]

What is the point of the 3 red led's on each board?

[ed12]

by looking at them u can tell the mains are working right thats point a
point b means there within range
point c is because if u look at the schematic u will note they are current loaders
for the down stream power

ed

[amandandme197]

Ok, I got ya. Thank you. What should I do as the next step?

[ed12]

if all is back toghter
i will post u a txt on test voltages

ed

[amandandme197]

I didntput it back together yet because I didn't know what else needed to be done, but I will do that tonight if I can. Thank you sir

[ed12]

ya if u have done the requested chks
then by all means go ahead and pop in the driver boards
BY NO MEANS PLACE IN THE OUTPUTS
all voltages i give u will be with refernce to ground
ie black probe which should be on your  -  on your meter to the case steel of the unit
unless other wises speced

ed

[amandandme197]

You mean the 4 output transistors or the speaker output plugs?

[ed12]

until this test is over with the 4 output transistors

on my pervouis post i made a mistake
for u..we will be switching the ground with the vcc when we do the - voltage chk
so at that point the red probe will go to ground and the red probe will measure
the minus=- voltage
this is because we are using an analog meter
my bawd sorry..
now with everything back in expect the output transistors
go ahead and place your 2 lights into the fuse holders >just tack them there<
u should find +40 volts dc on both sides of 1 light
and - 40volts dc on both sides of the other
if so...2 of your leds should be off >overload<,if so we order transistors and fuses
mica's and grease
this applys to 1 driver channel olny..as u olny have 2 lights
but just remove them out
and place them in the other driver board
and repeat step 1 and 2

and as a saftey measure here
give the main caps about 30 mins to drain down there charge..reason is there is no real load for them to work into
 the driver board will pull it off abit slow but it will do it

ed

[amandandme197]

Ok ed, call me stupid, but without the 4 output transistors, how would we know if they are bad?

[ed12]

as has been explained...
and stupied is not in this..
the outputs a darlington with internal resisters
it is all but impossable to chk them right with out a proper piece of test eq..
200.00+ dollars
the olny real test u can do is >chk for shorted transistor<
on the leakge test they will show bad on any meter
analog and or digital
u need a b-x-k transistor or a small pico job to do it proper
and it is just not worth the money to buy them as a 1 off unit..
it is cheaper to do it the way u are
and then order in the new stuff u need
u see the leakge test is a mind tester even for seasoned repair techs
without another knowen good 1 to ref to
it is a guess at best
if u had a shop like mine where i stock them it is a cake walk
but for u this is not the case

ed

[amandandme197]

No, I do remember yo telling me about that, I guess what I am trying to say is that if those 4 transistors are removed, how can we do any kind of testing? So I should unscrew all 4 transistors, and remove them before we do this light test, hook everything up as it was before the amp went bad, and turn the juke on, then do the voltage test?

[ed12]

yes yes yes remove them.....
now do not turn this amp on with them in place........
a nice thing to do here and we all do it
is mark them 1.2.3.4 and the hear sink the same way 1.2.3.4
this way u know where the new ones go....
DO NOT PLACE IN THE NEW 1'S UNTIL WE ARE
A DONE TESTING
B I GIVE U THE LOCATION ID
u see they are npn/ pnp matched pairs
as a rule they will come packaged toghter
ie 2 transistors in 1 pack..
ie npn/pnp for 1 channel
we do not mix them up..at all costs

ed

[amandandme197]

Got ya buddy.

[amandandme197]

Now the ones that are in there now are the ones i put in there. Do you think i screwed anything up when i turned it on then, and should i still number them since they may be wrong when i put them in?

[ed12]

please do as i requested
u are in the home run right now :3rd: base
lets not play games with it now
u have to under stand short of a dead short there is no way u can test them
a=u do not have a pair to compare to
b=u are using an analog meter
even i do not second guess myself in these matters
and i no longer have any idea as to how many amps i have done
there is a set prodocol here..we all follow it
it costs less $$$ and saves a boat load of time

ed

[amandandme197]

I will and i trust believe you. I was just trying to say I have the ones that I removed still (that were in it when i bought the juke), and I have the ones i put in after the amp stopped working a couple weeks ago, and that did not work as soon as I reconnected the amp. So i have 8 total is what i was trying to let you know, and that the replacements that i put in before i contacted you guys, that did not work. I will do as you say buddy, but just wanted to let you know that I had the originals still, and the replacements, all which do not work.

[ed12]

i understood u
from the start
u may have been shipped un-matched pairs
all to common when u buy the of fle-bay or even mouser/digikey
u must spec matched pairs..as i explained they the npn/pnp's will come toghter
in 1 pkg so u will get 2 pkgs of npn/pnp and the other will be the same
npn/pnp,they will be marked  >mp's<,this is the way u want them..
the reason i do not use the old 1's
a= the mains fuses blew..40v at 8amps =320 watts..? on a 250 watt amp max
that my friend is a dead short
same reason we will replace the micas..
mow on to the old and new
u can with the analog meter
rx1 or rx10
chk c-e c-b  bet u find a short there
but it is of no nomer..if the pairs were not matched to start with
the self biasing diodes would have snapped them...
u have to under stand the full theroy of your amp
it is a push pull amp..the outputs
with a qusi drive..the qusi drive makes it diferrangle
which in easy terms means the driver is just about always in a on state
and it is a postive feed back style amp..even more of a problem child...
just be glad u are not dealing with a mosfet amp..yours is linear
will not any near digital..thk the lord

back to the old 1's transistors
ever had a cd u loved skip..and used it as a frishbe ?..
use them as a lesson learned..move on

ed

[amandandme197]

I got ya now. No they were not sent as matched pairs. I ordered them all sepperate. I thought as long as they were pnp and npn, they were good. I see now what you are saying.  Ok, i will do all of what you said ed. Sorry if I got on your last nerve, i just didnot understand that they are supposed to be bought as a mp in the same packaging, thus making me wonder what was wrong. Ok, i will do as you said and get back to you. Sorry

[ed12]

never never say sorry to me
if u did not understand the rules
how would know how to play the game...??
and on my last nerve? i think not..this is a pleasure for me..trust me
my new gig with the rasberry pi will come as i want
i am just working out a few kinks in my head..
plus they put me on another med..which i did not want..
reason is simple..cannot ride my honda..and that 1 gets on my nerve
your amp is  :a: a pleasure to help u with,:b: i get to refresh crap i already know
no foul...

ed

[amandandme197]

Lmao, thank you buddy. Sorry about the ew med. I feel your pain

[amandandme197]

I just didn't want you thinking i was one of those "you can't fix stupid" types of people........lol

[lilshawn]

basically what's going to happen is: the transistors are a valve. if there is an issue with the preamp board it will drive the output transistors full on instead of leaving them closed until it's time to play something and drive the speaker coil.

if we measure the drive going out to that transistor and find anything odd, we know something is up and needs to be investigated further... if all seems good, we can plop them back in and HOPEFULLY be good to go again.

[amandandme197]

I got ya shawn. I have all boards back in, connected, transistors removed, and bulbs in place of fuses. Now i guess i will plug the amp in the amp outlet. I assume i need to connect all the speaker hookups to the amp? I will wait to hear from you before i go further.

[lilshawn]

no, we are just going to check the predrive. we won't need speakers for that. you can just have the amp sitting out on the bench for that test.

the lightbulbs are going to give you a visual indication indication of how many amps are passing through the driver board

[amandandme197]

Awesome! I hate lugging it in and out of the juke.

[amandandme197]

Both d6 led lights are lit. I unplugged it to be safe.

[ed12]

ok
so far so good
i will chime in ltr and help finish it up now
then we can order our new stuff
and u will have a working amp again

ed

[amandandme197]

 Also, no overload lights came on, so  I assume that is good as well........ 

[ed12]

ok
1 driver board at a time
place in the lights where the fuses were
turn amp on
of course U HAVE REMOVED THE OUTPUT TRANSISTORS
and see if the light come on dim/med/bright
if dim
turn amp off and wait about 30 mins for the caps to discharge
place lights in other driver board and repeat

at any time if the light comes on bright shut it right off
dim to no light at all  is all i will accept at this point
do that first then get back to with your results

ed

[amandandme197]

Ok, on the first board that had the blown fuses, the lights did not come on at all.

[ed12]

perfect
now do the other board
if it passes the musterd test
we order  matched pairs
micas/silcon grease
and fuses

ed

[amandandme197]

Sounds good buddy

[amandandme197]

Unsoldering from the first board now.

[ed12]

u are so colse to the home run i can just about see shawn on base..
just REMBER U ARE NOT USING THE OLD OUTPUTS..
or all is for not

ed

[amandandme197]

All clear. No lights.  Nope, all 4 of the recent outputs and the 4 original ourputs are put away. Just kept out the screws grease and 4 new insulators

[ed12]

order away
if u want i will chk my main line for matched pairs ?
as i trust them

ed

[amandandme197]

That would be great. As long as they are cheap enough, I will do that if you find anything. I will order some 8a fast blow fuses from ebay. So did the lights confirm everything seems to be good?

[ed12]

ok i will ask my suppiler in the am

yes they said the driver seem to work right

now before we drop in the new finals
we will with the new fuses in do a test on the final driver circuit
it is easy...we will olny be looking at  drive voltage to the base of the finals
to make sure they are not beening turned full on..this is where back about 4 pages ago i asked u if u had a audio source..u said no so i went this way..
same out come just a dif way of doing it

now the lights will be used instead of your speakers,for our final test
before we tie it back into the juke

side note here..i will be doing deep scan on this my main box tonight
it takes 14.30hrs to scan 6tb of drives
and yes i said terra bytes,so do not expect me before 6:pm est
i will be around tonight for another byte or 2..

[amandandme197]

Awesome buddy. That is no problem. No need to explain yourself, as I appreciate your help any time you are able. It means a lot. If it were not for you, and shawn pitching in when your gone, I would be lost. I am just greatful for any help.

[ed12]

my best price tonight
without my usual chit chat with the person in charge
is about 4.55 each..about 9.00 per matched pair
not to shabbey for on line..
but i will make the nessarey >hey dude< kinda calls tommrow

they are for the record
2n6284 and 2n6287
a swift nte crosses them to mp's
but i do not buy nte..........
my manual even places them right..
if u need i can get a scan for u..so we do not fault now ?
now mouser lists them seperate..this is bad for our app
i did not chk digikey yet but i will

ed

[amandandme197]

Awesome, awesome, awesome!!! That price sounds good to me Ed. I think that is pretty close to what mine were each when I bought them from  Allied Electronics, but they were not mp. Would I be able to pay you through paypal, or pay them through paypal (which ever one of you would be sending them)? The scan would be helpful if it is not a problem. I thank you buddy. Oh and they are the numbers you posted.

[ed12]

no u guys can do it
i willl just clear the lanes as it said....
and yes i will go get a pdf for it

ed

[amandandme197]

Thank you so much ed!! 

[ed12]

well
that took a little longer then i thought
27hrs
found 2 tracking
1 cookie
1 worm

after what i was told today
we can ditch the idea of >mp<..why i am out on as of yet..
but do not do any thing..i will dig in tighter
reason is i just want this amp up and running

ed

[ed12]

ok i have tracked down a pair

now short of ami-man having >mp's< ?

digikey
mouser

it seems the mp's went :eol: >end of life<
if u want i will nose around jukebox list or phono land
allen is a @ at phono land,and seems like he may come to the cause ?
i know i olny have 1 pair left..which i want for testing reasons
 that said,i will poke through my nte stock etc,if i have them your welcome to them
just please do not buy them from flea-bay...

nte 251 =2n6284 hfe=2400
nte 252 =2n6287 hfe=2400
thats what mkes them a matched pair  >hfe<

ed

[amandandme197]

Thanks ed, I appreciate it. Do you think I should get extras if they are that hard to find?

[amandandme197]

Do these look right on this page? They are expensive and require a 10 piece minimum on each trans,  but if i need them, i need them.



http://www.aliexpress.com/popular/pair-transistor.html

[ed12]

god no
i will find u a us house tonight
when i order parts
about 7.00 max

ed

[amandandme197]

Lol, awesome. Thank you buddy!

[ed12]

np
i am just getting the work orders for parts in order now
will post u a supply house colse to u

ed

[ed12]

mouser has them in stock 4.73 each
digikey has them at 5.30 each
this is quoted in canadian $$ if look them up as u are in usa
u will get usd pricing
>www.mouserelectronics.com<
>digikey<
the price i gave u was 1/2/3/4 off's
i buy in bulk 10+ so my price goes down of course

ed

[amandandme197]

WOW!!! Mouser has so many of each one. What would be the ones oto get,?

[ed12]

mouser # >863-2N6284G<
mouser #>863-2N6287G<

ed

[amandandme197]

Yor the man! Last ones I bought were not the g's. That could have been the problem, eh?

[ed12]

i do not about beening the man
but they are the 1's that match the closest to the specs
and they are :eol: yet..but thk u time to order 10 of each for my stock
if the dollar is right maybe 20 each

ed

[amandandme197]

Got ya. I am going to try and order 4 of each so i will have spares.

[ed12]

np
i just placed an order for 20-40 pieces
thank-u for this thread u jogged my mem..

ed

[amandandme197]

Thank you for the help. You taught me a lot. I just hope that when these 4 trans go in, the problem is solved. If not, i think I will seriously give up

[ed12]

before we pop in the new outputs
we just need to do a few tests
protcol calls for it to happen
do not forget the fuses either
your total cost should be about 25.00 plus del.

ed

[lilshawn]

Yor the man! Last ones I bought were not the g's. That could have been the problem, eh?

they just add "G" to the part number to identify that it's a lead free package.

EU nations don't allow lead in products. everything that makes up a product must be all lead free. that includes solder, the tinned legs on IC chips etc.

kinda funny, when you used to buy a pinball machine in north america, it had a nice orange vacuum plasma display. but because they had lead in them, in europe, they used a red LED matrix instead. course now, they all do.

[ed12]

ya shawn
most ppl would have thought that ment >general<
where it has a total diff reason...gov..fregging with indursty

ed

[amandandme197]

I got ya guys. I really hope it was my transers

[ed12]

in light of no light
we will do a final :drive test: without the outputs in
then we will hook up our lights to the output side with the finals in
and do a fast test..
if it passes ? we will make sure u are tied into the output transformers right
and pass around the beer for me and high fives for u..i think shawn
is on to scotch?

ed

[amandandme197]

Lol, that sounds goot to me. I will also supply the music.....lol

[amandandme197]

Well, I went ahead and bought 4 of each for a total of 8 transistors. This way i have spares.

[amandandme197]

Finally got my transistors and fuses.

[ed12]

ok great
tonight how ever do me a fav and just sit with them..
reason is i am beat...
if u want to do a chk ?..which i am up to
hook your probes to ground >black lead< and go to the output stage >transistors<
WITHOUT THEM IN....with your lights hooked up as fuses as u did before..
go to your >dc< range..lowest should be about 1x or 100v
and power the amp up and record the base drive voltage
there is to termanils 1 is emmitor the other is base
we want the base drive voltage..
record these..most important...
if they are right..we can deduce the drivers are working right or wrong..
there will be NO input singal at this time...
it is called :amp-idel:..
from there we can if all is right tie in the finals and new fuses
do a load test with the lights.. and audio
u will get the reason for that after these short tests

ed

[amandandme197]

Not a problem ed, I will do that and you can get back to me whenever. No need to do it tonight buddy.