Rowe Saturn Jukebox Amplifier problems

[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