Finlux 32FLD760P with Vestel 17PW20.v1

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

C801, sorry.

But the voltage across C881 should be OK! It's now 13V, instead of 5V... and the controller can run with this. So do you see 390V across main cap?

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

It reads 19.2v across when on, 18.2v when standby.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Now it is good. What happened to change that? Any glitches on screen now? 390V across big cap?

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I haven't seen any glitches on the tv, and the big cap when on reads 333v still.

The only difference now is that I don't have the back cover on, so it gets more aircirculation. It works best when I have a tablefan pointed at it.

With the back cover on it gets hot, you can feel it at the top. So I'm guessing something doesn't like the heat, and the only things I know that's plugged to heatsinks are the MOSFETs, but I'm unsure.

If in worst case it's unsolvable, I'm thinking of atleast modding the back to put in a big fan and make some circulation to keep it cool, atleast until I can afford a new PSU.

But I still want to see if I can fix this one, but it's up to you tom

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Well, it is odd, to say the least. Maybe the PFC IC itself is faulty.

The PFC IC should be "FAN7529" according to my notes, is this correct (you will need to remove PSU and check bottom for IC802.)

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

What would the PFC IC look like? I can't find any FAN7529 on the front, but I'll unplug it and check the back too.

Would help alot if I knew what I was looking for though

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

It's on the bottom.
Kinda looks like this
http://www.modtronix.com/images/so8.jpg

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

PFC IC confirmed to be FAN7529 on the bottom of the board, looks fine to the naked eye, soldering seems solid too.

[budm]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

"It reads 19.2v across when on, 18.2v when standby." That is what I expect it to be on C801 (33uf 50V) as I suggested in post 124, now it has lots of regulation head room. I would replace that cap and see if the TV will function correctly every time.
So the PFC FAN7529 is not the same as shown in my diagram?

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

The cap C801 has already been replaced with brand new Panasonic caps, 33uF 50V ones.

I'm not really that good at reading diagrams, so I can't answer you on that, but I have noticed that almost every pdf file I find about this board is slightly different with the numbers and names. Not sure why.

[budm]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

If that is the case, then I would check all the soldering works just to be sure. And now you also know what you suppose to have at VFMain.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I've checked quite a lot of the soldering joints underneath the board, I couldn't find anything but to be sure I reheated a lot of the joints to make sure there's no cold soldering, in my case it hasn't helped. I'm just not sure where to check anymore. I feel something might be funky with the MOSFET in the middle of the board, but I don't know.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Now it is good. What happened to change that? Any glitches on screen now? 390V across big cap?

Hey tom, in this post you made, did you mean the C801 or the C881?

In my answer when I said 19.2v when on and 18.2v when standby I was referring to C801, the small cap at the bottom right on the board.

Just making sure we didn't miss each other there

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

New problem now, I think something's dead.

Put the tv back together again, and lo and behold, it died after 5 minutes of a movie.

Problem this time is, it doesn't come on, the LED works, but it sounds like something's wrong with the 12v line. This is getting annoying, there's always something new popping up.

I really understand now why you buy new PSU's instead Tom, but hell, if I buy a new psu and it's the same vestel, it would probably just die again wouldn't it?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

really understand now why you buy new PSU's instead Tom, but hell, if I buy a new psu and it's the same vestel, it would probably just die again wouldn't it?

Yes but it at least would last 2 or 3 more years and you would have a chance to save up to buy a new TV, or fix an older, better built one. These damn PSUs have been the bane of my life. I have never successfully fixed one, despite at least 5 attempts.

Check 12V, and 24V voltages.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I'll get around to checking, I'm a little busy at the moment but I'll keep you updated.

The more the PSU doesn't want to work, the more I want to magicaly fix it haha, I do like the challenge but it's annoying to put on the cover only to have it fail immediately again, this is over the tenth time I've done that now! Grrr.

[ron77]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Ron77

Only recently spotted this post.This PSU has been around for some time now.Many updates of course.Have repaired many of them over the last 6 years.
In this set it does appear to be Ic 802, Fan 7529, that is the problem.When repairing these Psu's I do the usual voltage checks, standby, etc.Then I remove PSU plus all plugs cnnected to it from the chassis. Connect mains only to it, no other plugs. The psu is in on state as P on voltage is 0volts.

At the moment I am running a 17pw20-v2 on bench, a working one.Voltage across c819 is 392volts. Voltage supplied by D831 is 14volts varying only slightly.

Now I have connected a 17pw20-1 that has similar symptoms to yours. Across c819 reads 340 volts.All the output voltages, 24v,12v, 5v, 3.3v are OK.

Low voltage across c819 check circuit around Ic802. Could go on and on about this psu,but I won't. Knowing this psu reasonably well, think advice given earlier, buy a replacement panel, is good advice.As I have 15 of these panels, 5 working 10 not I was in a good position to research this one.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I'll have to check the voltages again tomorrow, I'm sure something new has failed because now it doesn't start at all again, maybe my bad soldering I guess.

We'll see tomorrow, but thanks for the input. I now know somewhat what to keep an eye on for problems, but I doubt I can fix it. If not then I'll just have to wait and order a new PSU when I can afford one

[ron77]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Ron77

Hello Serkai.

The point I was trying to make yesterday,was you have to get the voltage across c819 reading about 390v.If the reading is 333v the psu is faulty.I work on those psu's out of the tv.When I get that voltage reading 390v, is when I put the psu back in the tv, and not before, no point.I have repaired about 250 of these psu's.Would never start one without having every spare,that is, spare panels.

By the way, I am half scandinavian. Grandfather Swedish, grandmother, Norwegian.

[budm]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

The key point is the DC voltage on C801, if it is too low, there will not be enough voltage for the PFC IC to operate to get that 380VDC.