The NEW Build Your Own Arcade Controls
Main => Monitor/Video Forum => Topic started by: GMZombie on June 22, 2012, 09:34:12 pm
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ok so i have 2 of these chassis with no power. first i thought i would replace the hot. did that and no luck still dosent power up. now i setup my station so i was able to take some readings while its hot and here is what i have. from ac power in i had a 55vac/60vac right at the ac in on the black and white ac in wires. followed power on each side till it hit a d101 which is a 4 pin what im assuming a diode and when jumping from 1 pin to the next it goes from 55vac to 1.4vac and the 60vac goes to 2.0vac. just to be sure i checked it in dc and there was no volts. i checked r117 and there is no volts on either side. please advise next route of action as im stumped
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ok so i have 2 of these chassis with no power. first i thought i would replace the hot. did that and no luck still dosent power up. now i setup my station so i was able to take some readings while its hot and here is what i have. from ac power in i had a 55vac/60vac right at the ac in on the black and white ac in wires. followed power on each side till it hit a d101 which is a 4 pin what im assuming a diode and when jumping from 1 pin to the next it goes from 55vac to 1.4vac and the 60vac goes to 2.0vac. just to be sure i checked it in dc and there was no volts. i checked r117 and there is no volts on either side. please advise next route of action as im stumped
huh ?
120vac is not after the :bridge:
that should be 160vdc volt's dc
chk on the main filter cap,rem u are in :volt's-d-c: not volt's ac
ed
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ok i have located a bad dioed in the board d106 but when i take it out it tests ok. i checked it with another board that i have of the same type and it tests good in the board? also dc volts is 170 to the t101
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hi
ok now we are getting some where
170 vdc is a good sign :)
this means the powersupply front end is good :ie-input-filter:
but at 170 i would first look for bad solder joint's,blown fuse
that feed the hot circuit,could also be a dropping resistor
i will look up the schewmatic and get back to u
ed
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http://www.vidiot.ca/manuals/Neotec_NT-2X.pdf (http://www.vidiot.ca/manuals/Neotec_NT-2X.pdf)
here is the service manual with schematics in it.
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check the high voltage poly cap on the HOT collector
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i dont have a cap tester persay is there a way to check with the dmm.
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i dont have a cap tester persay is there a way to check with the dmm.
not really but last one of these chassis I fixed had a split on that cap which was quite obvious-like a small burn infact
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ill take some pics a second
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hi
if u are apt with a dmm
and have the chassic hooked up ?
turn it up-side down,carefull not to short anything
look for c425. there should be 125vdc there
now rem u are working with a smp style monitor
so the switch will switch up >tech term for starting<
if this happen's and u are not getting 125vdc there
then go to the :output: of the smps,there is a .47ohm resister at 2watt's
it act's like a fuse,it will be open..if so u have a hot problem >common<
u cannot read it in circuit..
ed
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ok so i did some checking and on one of the 2 chassis's i cant read the hot but when i pull it out it reads fine. the second one i can read in circuit but when i do it reads voltage on both sides checking black from collector and then red to base then emitter. checking between emitter and base i get 0. of course i get no volts from c125 but then i get no volts at r117 either.
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hi
ok when chking the hot
1 side of the meter is to go to common ground
the other side of the dmm is used to chk for b+ feed
the base will read small,the collector should read about 125vdc
the emitor is at 0
chk 1 side of l402
then the other that is your b+ feed
it then run's through the flyback to the hot transistor
u can tie the ground of the meter to ground side of
c116..
this should then tell u if u are getting b+
if not go back to the resister i asked u to look at
ed
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what is the number for that resistor?
NM i believe your talking about r117 which is .47 2w correct
EDIT: checked all of these and when it is hooked up i get no voltage. resistor is in tact at .6 ohms..so im not getting b+
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hi
right
and it is comman for them
chk the fet in the smp's
now u isolate the chassic as u are going to be on the hot side
of it :ie-117vac converted to 123vdc:
the fet is on the ac side after the bridge and input filter etc
ed
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well from gate to drain on the fet i had 167vdc of course i sparked it trying to test gate to source which freaked me out. i stopped shut everything off and waited a second. retried voltage check from gate to drain and it is still 167vdc.
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hi
your switch is not comming on
ic101
be sure it is getting it's voltage through r102
please rem u are on the hot side of it,:isolate:
if u are then your fet is south,there is no real test for a fet
in your case u sparked it
might be a good chance u blew it :open: and took the smps switch with it
ic101
ed
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yea from the r102 i get 49vdc. at the pin where the trace goes to on the ic101 im getting about 45vdc so it deff has voltage. so would you agree that it woudl probably be the fet and the ic101?
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hi
i just looked the spec for that ic +20vdc
+49 is a ?
also there is a soft start cap
c110 which is 1mf at 50vdc <problem child>replace
so 49 now becomes the magic problem
look into the fet
and prey the ic is not blown >not-un-comman<
but all hope is not lost as it will cross to a nte..:):)
ed
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i found a spot to get those ics only 3 dollars a piece so no big deal there. i did a voltage check from the pin on the ic that the resistor trace ends up going to, to the c110 and im getting 8.92vdc on that on each side. dont know if that helps. i can get the cap replaced and i do have a new fet. bought it when i bought the hot
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hi
ya let's start there
also rem d105 and d103 are high speed switch diodes
and doing a chk on them is just about use less, if u can find them replace them,there again high speed switch diode's
Industry Number : RGP10M
NTE Device Number: NTE558
RECTIFIER-SI,1500V,1A,DO-41
1500v/highspeed
ed
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you can try the NTC parts to substitute the diodes, but i've never had much luck with replacing them with anything other than what was originally there.
my experience has been they either blow right away or fail within a few months.
also be warned these parts are high voltage, they may test okay with the low voltages used in the diode test on the voltmeter but still fail when subjected to the higher voltage of the operating circuit.
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with the cap should i get a high temp high freq cap or just the high temp cap>?
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hi
on the input side of the smps
i would use a low esr high temp cap's
ed
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have some success on one board. got it fired up after replacing the ic101, fet, and that cap. only thing is the red dosent seem like its getting bright enough. could this be the tube?
second chassis not so much luck. figured since i already had the same parts as i bought 2 of each item to fix both chassis's i put them in as it was having the same issue with no power, i also changed the hot on this one as the old one was deff bad, but at first i didnt have that cap in. when i turned it on it made a squeal so i turned it back off. i hoped i didnt blow the hot doing this..i found a new cap and after installing it the squeal went away but the system still dosent turn on. i tested 133vdc at cap 425 and on pin 2 of the flyback along with 133vdc at the middle pin of the hot. when checking for volts over the hot i get nothing on each side. but when i check the hot with diode check and off i get from base to emitter .417 and from base to collector .417 with collector to emitter a 0
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hi
GMZombie
on the first chassic :no-red: i would want to do all the other test's
first,but if u have a rejuv handey or know a bud who dose chk the tube
it's 50-50 to say it's a bad gun in the tube without chking it's drive,etc
on the second 1
them reading's are all wrong
u should have full dc on 1 side and drive to the tranistor
.5,the emmiter should b at 0
i would just swap the hot transister out
and go from there
ed
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its not no red...i just had to turn the drive up all the way to see some red. ill try the hot replacement. luckly i didnt have to change the hot in the other one so i have another one lying around. i assume if it squeals it is broke.
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hi
that is :overdrive:
in the second 1
first 1
i may have read wrong
>have some success on one board. got it fired up after replacing the ic101, fet, and that cap. only thing is the red dosent seem like its getting bright enough. could this be the tube?<
u are right g2 could have been turned down
>
second chassis not so much luck. figured since i already had the same parts as i bought 2 of each item to fix both chassis's i put them in as it was having the same issue with no power, i also changed the hot on this one as the old one was deff bad, but at first i didnt have that cap in. when i turned it on it made a squeal so i turned it back off. i hoped i didnt blow the hot doing this..i found a new cap and after installing it the squeal went away but the system still dosent turn on. i tested 133vdc at cap 425 and on pin 2 of the flyback along with 133vdc at the middle pin of the hot. when checking for volts over the hot i get nothing on each side. but when i check the hot with diode check and off i get from base to emitter .417 and from base to collector .417 with collector to emitter a 0<
u have a hot problem
ed
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Switched out hot with another one still no power, did voltage testing again afterwards and now it seems as there is a alarm clock beep coming from the area around the Fet. tried putting the old one back in and still beeps.
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that tweeting is the SMPS in overload...it tries to start up then shuts down because of an overload or a short in the B+. after a very short period it then tries to start back up again. over and over and over.
sometimes it sounds like a tick sound, sometimes a flub, others a preet sound
you have a bad HOT or a dead cap in the high voltage (B+) section.
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so i figured out i switched out the wrong hot. i had 3 in my area but i only seen 2. the 2 were bad and now that i have the good one in it dosent beep anymore. it still dosent turn on but it dosent beep.
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so did i stump some peeps with this cause it sure has been stumping me. :dunno
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you can't just say it still isn't working, you have to give us a little more than that.
if it's not beeping anymore you need to check your voltages coming out of the SMPS. is there any at all? is it dead now?
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there is still volts going to the hot. 130vdc to be correct, its back to pre beep voltage levels. i switched the ic101 the FET, the Hot, and the c110 cap.
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there is still volts going to the hot. 130vdc to be correct, its back to pre beep voltage levels. i switched the ic101 the FET, the Hot, and the c110 cap.
how about the 25 and 12 volt lines? You need all of them for it to work.
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So my 25v is freaking out along with the b+ it starts at 125 and goes.up which.messes with.the 25.and the 12. I tried adjusting per the manual on r112 but.it.just made the volts higher
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I tried adjusting per the manual on r112 but.it.just made the volts higher
of course, that's what that pot does. Don't go adjusting it all willy-nilly. You can blow a whole shitload of components by driving the B+ way up and having nothing working. if your B+ is stable set it to about 120 or you marked the original start point set it there.
So my 25v is freaking out along with the b+ it starts at 125 and goes.up which.messes with.the 25.and the 12.
tell me. hook up the meter to measure B+.... apply power.... second by second, what happens. something is screwed up.
does it - spike up to 136 then down to 120 then slowly over 10 seconds rise into 129
does it - start at 93 after about 6 seconds it has climbed to 125.
does it - start at 125 and climb up to 130 after 4 seconds and then stay.
also measure the B+ on AC once it's stabilized....this will let you know how much a noise ripple is in the B+
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So the good chassis that I fixed I hooked up today and after some adjustments I got the red working and everything was going great. Then after adjusting the horiz posi on the mobo the chassis did its watch beep. Did I just blow the hot. Seems like its overloading. I don't have any voltage measurements yet as I haven't been at my bench. Just need some thoughts. It looked great before this happened but it didn't last long.
EDIT: Found the problem i had the old hot in and not the new one. put the new one in adjusted the b+ to 113.5 as per manual and it is on. but im curious should i look for anything else that could be going out?
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try changing c106 and see if it starts up properly.
you can also try and change it from a 100uf to a 220uf
this capacitor provides feedback regarding the B+ voltage. if it goes for crap sometimes it can keep the powersupply from starting up properly. upping the uf can give the power supply the little extra time it needs to startup before shutting down. It's quite common to change the value of the bypass cap on the pentranic chassis.
maybe try and shoot an e-mail to "support AT neotecgraphic DOT com" the guys there are usually pretty good about getting back to you.
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quick question i got the first monitor working again but when i try to adjust the horizontal phase or width it does nothing and it seems like the width is just to far for the tube. adjustments dont work. im thinking the side board may have a problem and was going to swap it out with the other chassis that i have but would like to know where to start on that side board? nothing looks burnt.
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If there is too much width it likely needs to be recapped.
no width control (turning width pot does little or nothing) is a sign the caps in the horizontal section are dry and need to be replaced.
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im getting in order to buy the caps for this horizontal board but the cap list is different in the schematics than it is on the board? should i just go with what is on the board. it dosent look like they have been changed before.
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go with what's IN the board. there are lot's of little tweaks and changes to parts throughout the lifecycle of electronic parts.
if they haven't been changed before, stick with those. if someone has messed with them previously, check against the schematic.
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i changed the caps on the horizontal board and the damn chassis went back to beeping again..grr i hate these chassis
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ok after i blew the first board already by changing those caps i figured now should be the time to put that one aside and work on the other one so i dont destroy it. after looking at the voltage on the 25v and the 12.5v im getting short spirts of that voltage but it dosent stay. i tracked it back to d107 which it is fluctuating at. that goes to the transformer and from there it looks like it goes to c113 and c112 but what should i be getting at that point? at c112 should i be getting the whole 170v or should it be less>? this chassis's b+ is at 130 at the hot and stays pretty much around there within a few vdc.
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do you have a schematic for this monitor...if not i can get you a copy.
you have to realize what you are looking at is an SMPS power supply.
basically they rectify the AC to a rough DC and then pulse it at high frequency with a MOSFET through a transformer.
this creates a weird half wave DC wave on the output side of the transformer...after you run this through a diode and a cap or 2 you end up with a relatively high amperage and high voltage DC power that can be used for various things. several taps on the out side of this small transformer will provide your B+ (130 or some volts) 5 volts, 12 volts 50 volts etc etc etc.
the main switching MOSFET has overload protection built into it...if the currant load on it is too high, the MOSFET will stop conducting for a short time before trying again. Tick tick tick tick...this is the sound of the MOSFET in overload. sometimes you can hear it sometimes not.
NOW, if the MOSFET is in protection, you need to determine the source of the overload and correct it. the output diodes are a good place to disconnect your various voltages to narrow down the section.
i recommend having the monitor out on a bench where you can get at it.
lift out one side of the output diode on one of the voltages. (leave the B+ section hooked up) and hook everything up and power on the monitor.
is it coming on? can you hear the "whine"?? YES?? good! pull the plug because that is your faulty section. don't leave it on long...it can be damaged. should only take 2-3 seconds TOPS.
is it still dead? YES?? okay not our problem area...try a different one.
TRIED THEM ALL? your B+ has a fault.
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heh yea i do have the service manual/schematics for this chassis. so i should lift one of the output diodes which should be d107 which is directly after the t101 and that controls the 26v and 12.5v correct? if this is correct i will pull this tomorrow and test out what you said.
On a different chassis but same model i have power and video but it seems when i adjust the fly-back brightness if i push a little bit on the dial some of the color will go away. Also cant seem to lock on vertical hold. it holds for a little bit then scrolls? Also i seem to be getting some over-scan lines but the fly-back is turned down low. does this seem to indicate a faulty fly-back? sorry for all the questions as i have 3 of these damn chassis to fix.
These chassis's seem to want to be the death of me.
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yeah just after the transformer. that will kill power to some of the sub systems (vertical deflection etc.)
there is a chip that handles the vertical deflection...sometimes a dry cap will cause the chip to act funny...sometimes the chip can partially fail and cause all sorts of wierdness. I would check the voltage going into the chip and see if it's low.
I'm not sure of the location or number. (I thinkn it's a "TDAxxxx or an la7835) I'll check the schematic at the shop tomorrow and let you know what one i'm talking about.
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hi
to start with the line's u are refing to are called retrace
if the flyback is turned down,replace all of the neck bard cap's + any 160v or better cap
they dry out and become bad
tda-xxx or la-xxx is the vert ic lilshawn
nailed it
do your self a favour and do not diode test the diode's,they are high speed high current
and u will not get .5v foward drop..more like .3 or less
they can not be tested the normal way
i have even seen what looked like perfect diode's fail under load
ed
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okay. lift D107 and see if it will power up. if it does you have an issue with something in that system. If not, it's something in your B+ (113v)
if it is something in your 25/12 volt system (vert deflection or sync chip sub systems) it's easy enough to start narrowing it down.
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ok i lifted it and one time i could hear the system click but it would not start up. it sounded like that before though. so something within the b+ part of the system
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while it's powered can you hear anything from the chassis? if the SMPS is in overload it usually makes a noise. it's constant while it's powered. tick,tick,tick,tick... or zzzt,zzzt,zzzt.... sometimes it will sound like a constant sound that will slow down to several seperate clicks that slow down to nothing after the power is removed.
trying to onomonopia is hard :-\
if the SMPS isn't starting there could be something there going on.
hook your meter to L102 and power on the monitor. are you getting a massivly flucuating reading or is it steady? (adjust your meter to read 200 volts)
if it's flucuating, leave d107 disconnected and disconnect L102 on the side that connects to C116. hook your volt meter up to the leg you pulled out. this will tap your B+ and kill everything running off it.
it should read around 120 volts... and it still doesn't start up (still flucuating all over) you probably got an issue with the SMPS (bad controller chip IC101 or MOSFET Q101)
if it comes on connect D107 and repeat the test.
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ok with d107 leg disconnected testing voltage at l102 gives me a reading of 148 and then it goes up a bit but i didnt let it go long as you said not to run it for more than 2-3 seconds with that out. it didnt make a noise at all no buzz or tick or anything. before i tried this i was looking at the b+ adjustment where it was and i dialed it back a bit to see if the voltage would go down since it should be around 113 at d106 am i correct? well it didnt work it didnt adjust it at all. so i just put it back to where it was.i have replaced the q101 before and the ic101 and c110 and the hot. testing voltage there is no voltage from the collector of the hot to either the base or emitter should that be?
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also l102 reading with the one leg off going to c116 and still d107 off 155 and goes up but only checked for 2-3 seconds
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The B+ can really only be reliably checked under full operating conditions.
under load the voltage will flucuate. with no-load the B+ will just run wide open.
if you connect L102 and D107 back in circuit and test the voltage at L102 it comes up but goes down to nothing correct?
if yes sounds like a bad HOT or bad flyback. a faulty flyback/yoke/B+ can take out a HOT in miliseconds.
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hi
insert a 100 watt 117vac light in line with the choke and diode
it will tell u the trick of the tail
and yes the yoke will suck up hot's in a heart beat
ed
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The B+ can really only be reliably checked under full operating conditions.
under load the voltage will flucuate. with no-load the B+ will just run wide open.
if you connect L102 and D107 back in circuit and test the voltage at L102 it comes up but goes down to nothing correct?
if yes sounds like a bad HOT or bad flyback. a faulty flyback/yoke/B+ can take out a HOT in miliseconds.
yup it went up for a bit but then kept going down. i didnt wait till it went all the way down but it went down into the 80's before i took it off. it spiked at like 130 then went down. I can take out the hot and do a diode test on it would that indicate anything or is there a surefire test for the flyback?
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hi
yes to the flyback
if u can sweep it ?
no to the hot..as it has a diode in it
the yoke is the same way..u need to sweep it...
ed
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so the flyback sounds suspect how do i do this sweep test?
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I'm still not conviced the SMPS is operating properly.
can we disconnect D107 and the output leg of L102. Hook a lightbulb (around 75 watts) to the output and to ground and see if it lights up nice and bright.
don't worry about running it longer this way. the supply will be properly loaded down. and the rest of the chassis wil be disconnected.
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I did hook up a 60w light which is all I had and it lights up bright
edit:
On the other chassis that i originally fixed but then it went out again i replaced the hot in it and it worked although i couldnt get the horizontal hold and frequency right. it ended up blowing the hot again. any ideas. i replaced caps on the side board except fore one cap which i couldnt find a replacement for. it was a big 4.7uf@50v cap at the top left on the side board
edit2:
would these Hots work for this chassis. i know the nte replacement as ive blown those and the original but when i was looking up a spec sheet it had the line 2sc4542 and the info and to the right of it it also had this 2sc4924 which here is the spec sheet
http://www.alldatasheet.com/datasheet-pdf/pdf/39085/SANYO/2SC4924.html (http://www.alldatasheet.com/datasheet-pdf/pdf/39085/SANYO/2SC4924.html)
here is the original spec sheet
http://pdf1.alldatasheet.com/datasheet-pdf/view/439593/ISC/2SC4542.html (http://pdf1.alldatasheet.com/datasheet-pdf/view/439593/ISC/2SC4542.html)
and of course the nte replacement
http://pdf1.alldatasheet.com/datasheet-pdf/view/9972/NTE/NTE2354.html (http://pdf1.alldatasheet.com/datasheet-pdf/view/9972/NTE/NTE2354.html)
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so would that replacement ic work for the hot?
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NTE is sometimes a crap shoot if it will work properly or not.
most of the time it's fine, but you can get it to work sometimes and it fails within hours/days/weeks.
if cost/availability is making obtaining originally specified parts impractical then go NTE, otherwise stick with OEM specified parts.
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so i did your lightbulb test and the light was bright and did not dim down. what is the next course of action?
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hi
the light is bright ??
no load....
u need a load
ie the sweep circuit is not working,the light should >dim<...but but not go out
rember ohm's law
ed
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how about with D107 connected...does the lightbulb still come on bright?
don't run this way more than necessary... it's bad for the vertical.
if it's way dim now or pulses/surges you have an issue with the vertical deflection.
if it's still bright, you have an issue with the horizontal deflection/high voltage.
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its still bright. so its a problem with horizontal deflection or high voltage
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im thinking about just pricing out replacing almost all the components on the power supply side that i an get reasonable. sound like a good idea? Also thinking it might be time for a cap kit too.
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if it still runs with the B+ disconnected and the B+ loaded with a bulb, your problem is with the horizontal deflection or the flyback.
check c415 for dark spots on the sides. check C421 and C420 as well.
you'll have to pick up another transistor Q402 "2SC4542" if you still have no luck after replacing that your flyback might be toasted.
if it'
i've never had much luck with NTE parts
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ok checked those parts didnt have a c420 it was not there on all 3 of the chassis so i looked at the 2 and they look good. no dark spots. would the ic301 or ic401 be the culprit for the horizontal deflection or neither? i know they are both deflection ics
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ic301 is vertical deflation. if you had good horizontal but no vertical deflection you would have a flat line left to right.
if you had no horizontal deflection but you had vertical you would have a line on the screen up and down.
if you have neither horizontal or vertical you would just have an intensely bright dot in the middle.
didnt have a c420
it's okay, they might have just doubled up on c421.
IC401 does supply sync timing signals to both IC301 and the HOT. There could be something up with that.,
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hi
ok i am confused
do u have the nessary b+ off of the smp's ?
ie 125/25/12 ?
if not look no more expect to that area..did u replace the fet ?
did u replace the slow start part of that circuit ? ic101? and it's slow start cap ?
if so and u did a non chassic load test as we both told u to do?,if so what did u get ?
ic401 is the horz drive ic301 is the vert drive ic
both circuit's use bi-polar output's,so they are predriver's
ed
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i did replace the fet, c110 ic101 and the hot. at d107 and d106 my readings fluctuate d107doesnt get above 16v drops when you hear the chirp or click, d106 at first goes up past 150v then goes down to as far as i watched it to 85. i noticed when it goes below 120 is when the hot starts clicking
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hi
well if it is not the flyback
u will need a yoke :it will do the same thing: with a tad different systom's
ed
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i dont believe it is the yoke and here is why. ive been fixing 3 of these nt27e chassis's. i have one right now that i have starts up but the horizontal isnt syncing and i believe it may be cause i need a cap kit which im waiting on but ive had working chassis on that yoke before.
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hi
fair enough
i have seen u went through this full chassic
it olny come's to 2 conculison's
or u missed a point,the light load is the master of all tail's
it tell's u the trick
ed
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the L102 i had you disconnect powers the HOT/flyback.
if you connected the light bulb (load) to the tail end of the disconnected L102 and the power supply fires up and is nice and stable, your problem lies someplace in the horizontal deflection or the flyback.
if the problem was somewhere else (vertical deflection, electronic subsystems...etc, etc, etc...) and you connected the light bulb (load) to the tail end of the disconnected L102... the power supply would still not come on line and would still be pulsing. See what i'm getting at?
I know you replaced the HOT, but if you have/had a shorted cap in the horizontal deflection or even a bad flyback, it would take it out as soon as you powered up. (since the flyback is powered from the pulses generated by the HOT)
It's going to be one stupid tiny little thing and when you find it you're going to kick yourself right in the butt.
<beginrelatedstory>
was working last week on a 500dx (the 27e's brother) in a 2 player head-to-head cabinet... would come on for about 3 seconds...vertical would fold over squash down and blip off. figured the vertical deflection chip (ic301) went bad and replaced it. tested overnight on a 500dx tube we have in shop <thumbsup> drag the chassis out to the game...lasts 10 SECONDS and it's cooked. the stink of burnt components fills the air. get PO and rip the monitor out tube and all and drag the thing back to the shop. replace the 301 again...fried. Yoke must be toast. pulled it off..stinks like dust and dirt but nothing like electrical. put in a third vert deflection chip and used our shop tube no problems. sent it out. tossed the original tube. I'll have none of that. Lesson here...never underestimate the sneaky nature of electronics. even if you think it's okay...you never know.
<endrelatedstory>
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hi
lilshawn
thank-u
ed
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fair enough i will go back and try the light load again. is it ok to leave it on for a little bit then. i believe then it will probably dim after it drops below a certain voltage b ut i didnt know if i could properly leave this running for a minute. also would like to pre thank you guys for helping me get this far. im fairly good with electronics but these chassis have driven me crazy..
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it would be best not to run it too long.
hook up a voltmeter to the B+ too as well. that way you can visually see it's working, and also get a reading of if it's stable or not since an incandescent bulb may appear on solid but could be varying by 20 or 30 volts and you can't see it cause it's so bright.
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as soon as i get back home im going to try this out again. i just got those cap kits in last night and capped one board already..damn there is alot of caps on this board.
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ok quick question there is a cap c19 on the pincushion board that i dont have a cap for but it is labeled as being in the kit. 6.8uf@50v. the only cap i have left though is a 10uf@100v would that work as i have 1 chassis that is working again but i still cant change my horizontal size. would that cap be the reason? board 2 i capped but still has a problem voltage at d107 still is going up and the 25volts on the d106 is jumping around randomly never going above 18v
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just do them one at a time... keep in mind the orientation (+/-) there are cases where some of the markings are printed backwards on the board. caps explode violently if installed backwards.
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:) good news first! i have 2 chassis's out of technically 4 working as of right now. have to wait on the 6.8uf@50v bp cap to come in for the pincushion board but no big deal. now i say i have 4 but really it was 3 from the kid and one parts chassis. come to find out my parts chassis just needed a few things re soldered and a hot and a fet. so that one works. i got the original working again with the horizontal working now but i had used the my parts chassis pincushion board to get that to work. the 10uf@100v for the 6.8uf@50v bp would not work. go figure. now i have 1 of that is from him that just wont power up. i have put in known good fet/hot's and checked the voltage at d107 and 106 and d107 dosent show any voltage while d106 shows steady 96.9vdc. i changed out the smps controller ic just to make sure but it didnt do anything. this board has had the cap kit done to it.
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ok i think i am going to just call that second board the parts board...anyways i have 1 more that when taking voltage my volts at the hot are 123vdc. i checked the usual places and they are all in spec im getting my 124/25 volts out at d106 and d107 but the system dosent turn on. can a hot be band and not chirp make a sound>?
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:angry: :angry: :angry: RANT: Damn neotec chassis's...i dont get it all i did was change the damn caps and now i get the voltage problem again where the voltage is fluctuating at the diodes to check. d107. damn it i knew i shouldnt have screwed with the caps but i had the cap kit for it and needed to get the horizontal width working...now back to stage 1.how exactly do i need to check the smps controller chip. pin to ground or cause its on hot side pin to a pin from the filter cap?
EDIT:: fixed it. rethought about it and forgot to readjust the b+. now it starts up again
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ok this last chassis has me puzzled. still the 27e and it has steady 114vdc at hot center pin. i have 26vdc where needed and 12vdc where needed?? I even replaced the flyback just in case and it still wont fire up? whats going on
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if you have the schems then locate the b+ pin on the flyback,desolder that pin and add a 115vac light bulb across the pin and ground
if it powers up and the voltage is correct and stable then power supply is ok and fault is on horizontal deflection as you have proved its not flyback
last neotec i worked on one of the high voltage poly caps on the hot collector was shorted
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where are these high voltage poly caps you talk about?
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the big orange blobby looking ones.
check them out...look for dark spots on them. sometimes they will give themselves away like that.
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are we talking the really orange circle ones or the more fatish square ones?
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(http://www.faratronic.com/Upfile_pro/sphoto/20071222104520530.jpg)
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need to read them with a cap meter-you can't guess if they are ok
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with reguarding a cap meter can i just get one of the 30 dollar cap meters on ebay? like this
http://www.ebay.com/itm/VC6243-LC-Digital-Meter-Inductance-Capacitance-Cap-DMM-/300559460479?pt=LH_DefaultDomain_0&hash=item45fabd687f (http://www.ebay.com/itm/VC6243-LC-Digital-Meter-Inductance-Capacitance-Cap-DMM-/300559460479?pt=LH_DefaultDomain_0&hash=item45fabd687f)
or
http://www.ebay.com/itm/General-CAP1500-Digital-Wide-Range-Capacitor-Tester-/190754909170?pt=LH_DefaultDomain_0&hash=item2c69e0ebf2 (http://www.ebay.com/itm/General-CAP1500-Digital-Wide-Range-Capacitor-Tester-/190754909170?pt=LH_DefaultDomain_0&hash=item2c69e0ebf2)
or would it be better to get a more expensive one?
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yeah second is fine
first is limited in range but good if you want to read deflection yokes
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i bought the second one. should be here in a few days i hope.