Finlux 32FLD760P with Vestel 17PW20.v1

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

OK, since Vcc is OK, do you see D823? What is on the negative end of the diode? (with black probe on the chassis.)

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

0v, checked both sides of it to be sure. That side of the board is completely dead right now, I really wonder why...

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

OK, across PL111, the red connector, what resistance do you measure?
(Power disconnected.)

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

With DMM set to 200k it measures 27.1 and rising (slowly, slowly), I'm not really sure if I'm doing it right. Resistance on the red connector in my picture, with the power cord unplugged from the wall? Btw it says PL811 on the board, if that makes any difference? Found no PL111 anywhere.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

PL811 is what I mean, sorry.
Mkay, not shorted.

I wish I knew where to look now but I am thoroughly lost.

Did you install the grounding strap connecting frame to PSU?

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Yup, indeed I did.

You know, I'm thorougly lost too. All I did was change caps to new ones, tested and not working, and it didn't help to change back. I just don't get it, how can half the board have no connection to power whatsoever from just that?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

ESD damage can cause that but that's rare with PSUs.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Hmm, ESD... But wouldn't that be noticeable somehow, somewhere? I make sure to ground myself before I play with the soldering iron, and I unplug everything nice and neat.

I don't get how 2 caps could do this, as I'm pretty sure it's not ESD but you can never be certain I guess.

Just an idea, what about the big thing with yellow tape on it? I'm guessing that part is made to shove electricity around, what if it's broken?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Which big yellow thing?

ESD can manifest itself in many ways.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I'm not sure what they're called, transformers?

Do you remember in the beginning when I said the psu makes a beeping/buzzing sound when plugged into the wall. As of now it's completely silent. The sound came from somewhere around the big main cap or top right on the picture. I'm thinking something there is dead now that it doesn't make any sound anymore.

It's like the red line I drew is a moat and no power anywhere whatsoever gets across it to the bottom half, doesn't matter where I try, it's stopped. Whatever's supposed to send the signal to let power through it's gone.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Yeah, if there's no standby power it won't do the power-on self-test where it fires up the PSU, so you wouldn't hear any noise.

I think you mean transformers... they're pretty reliable coils of wire. Very rare for them to fail, and especially not instantly.

Your best bet I think is to browse free/cheap ads and pick up a similar Vestel-based TV (you can check parts sites to see what boards are used) with e.g. a smashed screen for the boards. Unless you're sure you cannot get the PSU. You will have to track down the cause of the current failure and that of the original failure, and I don't know if that's practical without a scope and swapping lots of parts.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Yeah, I'm leaning towards getting a new PSU, it's just the whole giving up part is pretty hard. I just don't understand how it went from working, but unstable, to completely dead from changing those caps.

Sucks big time haha.

[selldoor]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I thought the big transformer looked a bit burnt - but they do get hot.
How about checking/resoldering the joints on it.
Also are those type of caps polarised or can you put them in any way around.

Post apicture of the underside?

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I have done some checking and resoldering on most big joints, I can't really tell if it's burn or not, it's just dark coloured but not charred or anything.

The caps are polarised, minus to the right in the picture, or closest to the side of the board. It's even marked plus and minus under them on the board.

I'll see if I can get a picture of the underside! Not the best camera but, it might work. Can't find any backside pics on google. If you can take on of your board I can mark if anything looks funky, just in case.

[LEEDASH]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

sorry i have no info on your model,-tom i know your a busy man on here,but any advice on my model (onei)

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

If I don't post I don't have anything to add...

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

The camera on my cell is too bad to get anything clear, sorry. I did however notice that I might have touched a small black rectangular thing on the backside when soldering the caps on, it's barely visible but it wouldn't surprise me.

I'm not really sure what those things are or what they do, but it's on the same line that should give standby and it doesn't!

Edit. Touched it with my soldering iron that is. I wouldn't be surprised if that's the damn fault, so small but so dependant...

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

What's the refdes? E.g. for that chip you read off, "IC802".

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

EUREKA! It's alive!

It WAS bad soldering on my part, I hadn't noticed a tiny strip connecting the 100u/50v cap on the backside to another spot, so it was unconnected.

I managed to get it all back together now and the power works, the tv comes on and I'm currently watching a movie to make sure.

I'm not sure what the refdes was but atleast now I know it's not that problem. Perhaps, doubtfully, the main problem is gone now? I'm using the new panasonic caps instead of the old ones.

Edit. Gosh, I sure did feel stupid there for missing that. Atleast now I know not to give up on it just yet. And well, it's the learning process I suppose, good thing I have my magnifying glass

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Haha, nice. Check the PFC cap voltage. If it comes up to 390V you may have fixed the problem.