Finlux 32FLD760P with Vestel 17PW20.v1

[Serkai]

Hey there fellas. First time poster here but a bigtime lurker since a week ago when I got this tv from my uncle.

First I want to describe the problems, which are somewhat random.

In the beginning the tv works fine, but the sounds starts to crackle when it heats up which led me to unplug the speaker wires and use an external audio amp, but just a little while after that I notice the screen flickers terribly when there's too much white in the picture, eventually if I don't lower contrast and brightness the whole screen turns white and stays like that until I turn off and on the tv.

A while after that I started having problems getting it to turn on again, the blue led was lit constantly and it tried to start up when I pressed the remote, but went back to standby. Eventually it would turn on and work fine for a while until I had to start it by remote again.

Then came the flashing led problem, where it got stuck until a random time had passed. I could try starting with the remote or powerbutton but nothing helped.

At this time, I came to the forums here to search for help and found many and interesting answers and ideas. My own ghetto solution was to unsolder the 15nf1000v polypropylene caps (correct me if I'm wrong somewhere) then solder some long wires there, so I could glue the caps to heatsinks to keep them cool. This has helped quite a bit with both the white flickering and the stuck in flashing led problem, but it still turns off to standby mode occassionaly.

If I let it sit for a little bit I can start it again no problems, but the fault is persistant.



I know I need to swap some parts inside, definitely the 15nf1000v ones, but I wanted to ask here first if there's any more perticular parts needed as I'm on a very very very tight budget, so buying a new PSU isn't optional (I'm looking at you tom66 )

I don't have the gear to check if the 330v at supposed 390v problem exists in my tv, but I wouldn't be surprised if it does.

Thanks for reading all this, I hope it can help you to help me, anything from ideas to concrete evidence is helpful, I'll keep my soldering iron warm until then.

- Pierre

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

At this time, I came to the forums here to search for help and found many and interesting answers and ideas. My own ghetto solution was to unsolder the 15nf1000v polypropylene caps (correct me if I'm wrong somewhere) then solder some long wires there, so I could glue the caps to heatsinks to keep them cool. This has helped quite a bit with both the white flickering and the stuck in flashing led problem, but it still turns off to standby mode occassionaly.

Well, I've never thought of doing that... it's... innovative, I suppose.

Yeah, you really need to replace those capacitors. The symptom you're seeing is very typical when those capacitors fail.

I usually replace the PSU board because in many cases it ends up being cheaper and easier (I value my time, too) it's only about £20 on eBay, the caps are about £4 including delivery but I've had far too many other issues on these boards to do that any more.

You can use any 500V rated DMM to test that capacitor. I've only encountered that issue once; the most common is those poly caps failing.

7 out of 8 of those Vestel I have repaired have all had symptoms similar to this. But usually powering on and shutting down after 5 minutes, or getting stuck in standby, or a blinking power LED.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

7 out of 8 of those Vestel I have repaired have all had symptoms similar to this. But usually powering on and shutting down after 5 minutes, or getting stuck in standby, or a blinking power LED.

Yeah from all the forum posts I've found here and there it seems those vestel boards aren't very long lived.

It saddens me a bit to think about all the tvs that are being dumped because one bad component, I guess I try to save as much as I can on resources used in manufacturing otherwise.

I did have the same problem with it shutting down every 15 minutes, give or take 30 seconds pretty precisely, but then, I'm guessing due to heat, the time it took for it to shutdown decreased until it eventually was just flashing and wouldn't start at all.

The idea to cool the caps came from another post here from someone, shikaru or something, where he said that the tv died when he heated them with a hairdryer, so I figured doing the opposite would help.

When I get my money I'll change the caps, as well as the other parts usualy found in those repair kits you can find online for this model, just to be sure and to hopefully extend the lifetime.

If it doesn't work, I'll come back and haunt you guys



Btw, I don't really have that much experience with actually measuring volts and resistance, only soldering and guessing my way to a solution haha. Still dreaming of one day having the money to afford my own little workshop with all the equipment. Mostly as a child I grew up seeing both my uncle which was a tv and radio repair guy and my dad being an electrician made me want to be one as well.

Either way, thanks for the answer tom!

- Pierre

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Alright, time for an update!

I've ordered the caps that need changing, I'm 90% certain it's them now.

When I get them I'll take some before and after pictures, try and show what problems I'm experiencing and hopefully, the end result if it's a lucky operation. I hope this will help anyone in the future coming along with similar faults and hardware.

- Pierre

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Another update!

I've changed the 15nF 800v caps, went smooth as expected.

However, my problem still remains.

When I listen closely to the PSU I can hear an electrical buzzing, kind of like "beep, beep, beep" as I presume it's trying to charge up but fails, and then retries. The blue LED in front was blinking at the same speed as the sound, and no tv came on.

I also noticed that if I turn on power, sometimes the LED stays on as it should, and sometimes if I keep holding down a channel button on the side it actually comes on, so right now my tv is on. I can live with it being hard to turn on, but I fear the problem with the screen turning all white if the brightness and contrast is set too high after a while isn't gone.

Any more ideas as to what I can do, besides ordering a new PSU? The thoughts I've had myself so far is transistors or MOSFETs, perhaps even the really big cap?

Thoughs and speculations are welcome, I hope I can get it back to working standards.



Thanks, Pierre.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Can you check the voltage across the big cap? Care high voltage - expect around 325V in standby, and 390V when powered on.
This is why I always replace the PSU on these models... far too many different faults to say it's "just those caps..."

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I'll see if I can find a DMM somewhere, my dad borrowed mine a while back.

Another thing I just noticed since I plugged in the speakers again. The closer the tv is to fail, the more crackling noise it makes through the speakers.

I had the contrast on 25, heard some small crackling and some "artifacts" occuring on the tv, then I increased the contrast gradually and the crackling and disturbances got worse until it finally just turned... Bright :P

It's not always white, it's just any color that just gets stuck there no matter what I try to do, only thing that works is restarting the tv and even then it comes back almost instantly if I don't lower the contrast and brightness to barely visible, which still produces the problem but just not as often.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Perhaps if the voltage across the cap is good do a service reset.

Menu 4725 (quickly & only on analog channel) then select FACTORY INIT, I think.

[vinceroger69]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

might be worth checking the parts on your board that are listed in this kit incase some items on your board are faulty you might need a esr meter though to check the caps
http://www.ebay.co.uk/itm/lcd-tv-pow...item27cea2f774

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

might be worth checking the parts on your board that are listed in this kit incase some items on your board are faulty you might need a esr meter though to check the caps
http://www.ebay.co.uk/itm/lcd-tv-pow...item27cea2f774

I bought all those parts except the transistors, or what those three-legged monsters are called. Guess it could be one of those as well.

The service reset didn't seem to do any difference, not even sure if it worked?

Amongs the many options, there's full tv reset (or something) which I pressed, but it doesn't even take a second and it's back to the normal no signal screen with the problem still there.

Gotta find a DMM somewhere.

Edit. The problem described in that link sure seems to fit my description perfectly, and the only things I haven't changed are those transistors.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

If you go into picture mode (I think?), you may be able to get some more life by turning the BACKLIGHT setting to maximum (oddly, a higher backlight setting in the service mode makes the backlight run dimmer...)

[vinceroger69]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

i not sure if both transistors are fitted to your board this is of another post i have been reading
Replace C878 (its a Polypropylene capacitor) with 15NF 1600V

There is an other Polypropylene capacitor, can´t remeber boardnumber but he looks exactly like C878. Replace again with 15NF 1600V Cap edit C877

Replace C801 with 33UF 63V

Replace C892 with 100UF 50V

Replace c817 with 220uf 25V

at least you have to replace IC829 with an 78L05 (if available on your board)

if your board does not contain IC829 but Q809 you have to replace Q809 with BC337

tom maybe able to advise you how to test these if fitted to your psu

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I'm trying to get my bluetooth to work, so I can upload my not so great cell phone pictures.

The polypropylene caps are both changed into new panasonic ones. I'll have a look at the other caps.

I get the feeling though that the problem has to do with either the big cap or those IC829 or Q809 components.

So many guesses. However, I found out what makes the elecrical beeping noise, it's the big cap. I tried the roll of paper trick someone else here wrote about and listened, and it's clear it's from the big giant cap with the high voltage, if that helps any?

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I'm sorry for the low quality of the video, it's pretty dark but I think you can see what the problem is. The pictures didn't come out good either so I'll see if I can get any better, and I found a DMM I can borrow so I'll soon have some readings on that big cap.

Apparently youtube can't handle my cells avi format either, since there's no sound. What you're supposed to hear is the crackling from the tv's speakers that increases when the flickering does.

http://www.youtube.com/watch?v=zNXVJ...ature=youtu.be

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Looks to me like the power supply to T-con or main board is unstable, which can be caused by the PFC circuit failing on this model especially in Europe (230VAC.) In UK (240VAC) it has just enough to run main board but occasional crackle/pop from speakers or flicker from backlight.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Hmm, sounds interesting! Care to explain more in layman terms? Haha.

Is there anything perticular I should do or look at to find out? Pull some wires and see if it helps or heat and cool parts?

Biggest question I have is, would what you just said mean that I have to replace something else, such as the T-con or mainboard, or are they reparable? Because I'm not too sure on what's what when I just look at the boards without googling and asking, I just know how to solder and look for info so far

I googled again and found out that me and another forum user here, Shikuru, had the same problem. Or most likely, I'll reread that thread once again too see if I can find anything out.

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

I suggest you buy, beg, borrow, steal or find a DMM, measure the voltage across the capacitor, and see if it's nearly 390V or not. Then test the outputs of the SMPS: in particular the 5V and 12V are important, though the 12V is most often used for both audio & T-con.

T-con handles the conversion of main board signal into drive signal for TFT LCD panel.
Main board handles conversion of analog TV & digital TV signal, plus HDMI, component, composite, SCART etc. into signals for T-con.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

DMM acquired! I only have one question, what is SMPS? Connectors?

[tom66]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

SMPS is the 17PW20.v1 unit.

If you post a picture of your PSU, I will highlight checks to make.

[Serkai]

Re: Finlux 32FLD760P with Vestel 17PW20.v1

Alright, finally managed to get a decent picture!

Please don't judge my shoddy repair of the pp caps, I was to eager to test the tv to replace the wirings I had made earlier.

I can guarantee they do not short circuit or come in contact with anything harmful, it's just not very beautiful is all.