RCA 32V432T Possibly Bad Fly-Back Transformer?

[Spork Schivago]

Just got this TV a guy gave me. Said he was throwing it out and asked if I wanted it. I'm attaching a picture of what it does. Would this be a bad fly-back transformer? If not, any ideas what else might cause this? I looked at the capacitors and they didn't look bad. I did not test them with my ESR meter yet. I was reading on-line that if the horizontal lines where going across the top part of the screen, it could be a capacitor but because they're on the bottom too, I don't think it is.

Thanks.

[Mrx3750]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

No your flyback is working. You have a picture.

I'm seeing retrace lines and what looks like collapsed vertical. Start checking caps in the vertical section, and around the flyback.

Also check for bad solder connections around the tuner, HOT, and vertical IC.

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

Thanks for the reply. I don't know a lot about TVs. I will try and find a service manual. I think I know where the flyback is. I've attached a few pictures. I think it's the big black thing. I know where the tuner is. Not sure what a HOT is and I have no idea what IC is the vertical IC. I can easily see three ICs on the board. An 8-pin, 16-pin and a 64-pin. Thanks again for the help. I won't be back until around 8 or 9 tonight.

Spork

[tom66]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

The vertical driver will be a big heatsinked IC which connects to the coils. It will be distinct from the HOT, which is near the flyback.

[Mrx3750]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

I think your vertical IC is working because I see half a picture. Resoldering it wouldn't hurt though.

I think you have bad caps in your vertical circuit.

[RON_CET]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

attached is a schematic, note vertical ic is IC301 if you have a dvm post some voltage readings of IC301 using cold ground (ex:tuner shield) for your ground

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

attached is a schematic, note vertical ic is IC301 if you have a dvm post some voltage readings of IC301 using cold ground (ex:tuner shield) for your ground

Sorry for the late response. I am helping my friend remodel their house (ie, put up sheet rock, tape and mud, paint...) I've been trying to work on the TV on the side. I'm going to have a little bit of time in the next couple days so I should be able to devote that time to working on it. The readings you asked for are as followed:
pin 1: 0.5 vAC
2: 0.140 vAC
3: 7.37 vAC
4: 0.034 vAC
5: 7.69 vAC
6: 7.10 vAC
7: 0.039 vAC

Thanks.

[Mrx3750]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

Have you looked at the caps in that area yet?

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

Have you looked at the caps in that area yet?

A little bit. I have the Atlas ESR 70+ meter and some of the caps by the flyback where reading leaky / in-circuit. They where mostly 10uF caps. I have a feeling when I unsolder them and check them again, they'll read fine. How do I know what the ESR is supposed to be for the capacitors? Is there a general chart or something that can help me?

I accidentally took the readings in AC mode on my DMM. It was a bit late and I was tired. I'll retake them after my appointment today with the DMM in DC mode. Sorry.

[redwire]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

I would check C302 (near IC301 TDA8177 vertical osc/op.), it sets the ramp linearity for the vertical oscillator. If the vertical problem changes a lot with brightness being turned up or down, it might be power supply weakness or the x-ray protection (C250/C251) activating - which can lead you on a goose chase...
Looking at IC301's pin DC voltages should help

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

I would check C302 (near IC301 TDA8177 vertical osc/op.), it sets the ramp linearity for the vertical oscillator. If the vertical problem changes a lot with brightness being turned up or down, it might be power supply weakness or the x-ray protection (C250/C251) activating - which can lead you on a goose chase...
Looking at IC301's pin DC voltages should help

I got the voltages in DC!
1: 3.117 - 3.12 vDC
2: 15.02 vDC
3: -9.89 - -10.15 vDC
4: -14.46 vDC
5: -2.069 vDC
6: -1.204 - -1.207 vDC
7: 3.344 vDC

Some of them where jumping a little. Not much more than a couple thousandths of a volt though...except for pin 3. That was jumping a bit more. Would that be because of the bad cap?

I think I found the problem. First off, I do believe there's something wrong with my meter. When they're out of circuit, they test fine. But in circuit, some read way off. Here's the readings of a few... The first number in μF is what it's supposed to read. After the = is what I read. I don't think there's anyway a 10μF cap can reach 553μF. On a previous board I worked on, I was getting similar readings but after unsolder the caps, they read fine. I have a feeling these will too....minus the one with >40 ESR. I undersoldered C251 and it still reads >40 ESR.

C250 47μF = leaky, ESR 2.0Ω
C251 4.7μF = 2.45μF, ESR >40Ω
C301 220μF = 1112μF, ESR 0.08Ω
C302 100μF = 86.28μF, ESR 1.12Ω
C303 10μF = 553.2μF, ESR 0.17Ω
C308 220μF = 1102μF, ESR 0.11Ω

C251 is a 4.7μF 50V cap. Can I replace it with just any new 4.7μF 50V cap? Having trouble finding one from Radio Shack. Once I replace this, should it work? Or could more be blown? I found a 4.7μF 50V cap by ELNA (CE-BP). It reads 5.10μF, ESR 0.72Ω. It's fairly old. A friend gave me a bunch a long time ago when he owed me money. Do you think it's smart to use it? Thanks.

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

I found a 4.7μF cap from Radio Shack in a mixed cap bag. I replaced C251 with the new cap and it didn't fix the problem. I do believe the screen looks different now. There's still an issue some wheres else though. Should I post a picture of what it looks like now? I still see some retrace lines.

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

Here's some new pictures of what's happening now. Before I turned the TV right side up, I tried using a mirror to look underneath it to see if it was fixed and I believe I still saw some retrace lines. After turning it right side up, they appear to be gone. Not sure if that's because there's a bad solder joint some wheres or if it just needed to warm up a little or what.

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

If the vertical problem changes a lot with brightness being turned up or down, it might be ...

The problem does not change with the brightness being turned up or down.

[RON_CET]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

yes another image please,also from looking at those last voltage reading you posted,those readings look very good,this chassis which is most likely a M134 is prone for eeprom corruption causing this vertical issue your having from the first picture you posted in your #1 post.IC001 is the eeprom ,also this chassis does use two different types eeprom, you would need to search for that using the complete model number (Example:32V432Tyx5) most of the new RCA eeprom already come preprogrammed,but there might be some minor changes possible for either slightly under scan vertical and horz which you would need the the alignment data information on how to access those parameters which I can provide if you need them.

[RON_CET]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

OK now from those additional images I would have to say eeprom corruption of adjustment parameters of vertical height,vertical linearity

Also Caution !!!! do not play for long periods with that collapsed vertical issue unless you reduce the G2 down to barely low visibility of issue on screen or you will have a phosphorous burn of that reduced vertical etched into crt

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

Hello and thank you. It's definitely 32V432Tyx5 for the model number and the chassis is M134C. Where's a good place to get one of these eeproms from? I cannot seem to find one on E-Bay or Google. I typed 32v432Tyx5 eeprom. Any other suggestions?

Also, we don't have much money. That's why we fix stuff like this and try to sell it. We usually give the cash to my parents to help them with their taxes on their house and stuff, however, because it's a bigger TV, I think I'm going to give the TV to my mum. Any idea how much it'll cost? Probably no more than 20$, right? Thanks.

[Mrx3750]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

I'm not so sure the EEPROM's corrupt. You changed out a cap and got a very different image. And were I to hazard a guess, if there's one bad cap, there's probably more.

I'm just going by the number of TV's I've fixed with vertical issues similar to yours. Are there any other caps in the area you can check?

And actually your meter is fine. You need to test out of circuit. Remove the caps one at a time and test out of circuit. Replace any that test low or have high ESR. Then if the image is still messed up, look into getting an eeprom chip.

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

... Are there any other caps in the area you can check?

And actually your meter is fine. You need to test out of circuit. Remove the caps one at a time and test out of circuit. Replace any that test low or have high ESR. Then if the image is still messed up, look into getting an eeprom chip.

I tested all the ones inside the metal heatsink cover IC301 or whatever it was. Just so I got this, if the ESR is high, take it out and test. If the capacitance is low, take it out and test. What if it's incredibly high? Like 50x for the capacitance? Do I have to remove them as well? And as for these that are ready leaky, could that actually cause a problem? I know it's not right, but I thought I read some wheres that a lot of electrolytes leak and you don't have any problems. I'll remove all of them if I gotta. Just trying to get a better understanding of all this.

Also, there are some big ones that I'm worried about testing. How do I discharge them? And there's some places on the board that say stuff like C402 (just an example) and instead of an electrolytic cap, it'll have like a red square one or a green square one...can I test them with my meter? And any more ideas as to what area I should start checking them? There's a bunch on the board. Should I start by the part on the back that says HOT or near what I think is the flyback?

Do I have to use the same voltage? If they say 22μF, 250v, can I replace it with something like 22μF, 125v?

Thanks.

[Spork Schivago]

Re: RCA 32V432T Possibly Bad Fly-Back Transformer?

C442 is a big capacitor. It's 22μF, 250v. It tests fine and I resoldered it, however, it wiggles. Like one of the leads are loose inside. Could that be a problem? It's next to the flyback transformer.