Philips 37PFL5603D. Image fades out slowly

[edugimeno]

Hi There!
I have a friend who owns this TV set.
The symptom is that when power starts up, it shows (almost) the whole image correctly, but after some seconds, the image starts to fade to black, slowly, from one side to the other, like it wipes sidewise.

My friend took it to a service shop and they diagnosed "Bad Main board". so he found a replacement main board online and just today I helped him swap it.

Problem persists.

This TV only has 3 boards:
-Main (just swapped)
-PS (probably not the culprit)
-T-Con (suspect)

It seemed to me that when I pushed the T-Con board it kinda improved.
Is this going to be one of those that needs a AS15F replacement?

I had a Samsung TV that needed a AS15F T-Con rework but the symptom was a permanent blueish color in the whole image

Thanks!

[CapLeaker]

Re: Philips 37PFL5603D. Image fades out slowly

Your symptoms sounds like a Tcon problem to me. Post a picture of your TCon board.

[edugimeno]

Re: Philips 37PFL5603D. Image fades out slowly

Yes to me it sounded like T-Con too, but I don't have much experience
I can't take that photo today as after manipulating the TV a lot yesterday, it ended up working fine, I pushed everywhere and maybe the AS15 chip got stuck to the board.
The thing is..I went back to a french guy who offers his repair service for T-con boards, he had already fixed one for me for another TV-set, and after describing the symptoms on this one, he said: "You have a bad lcd panel"...

Is there an easy way to determine where's the issue? Whether panel or T-Con? I still have to wait for the issue to come back, maybe it needs to heat up a little

Thanks!

[arenat]

Re: Philips 37PFL5603D. Image fades out slowly

Probably bad panel , check this link .

https://www.youtube.com/watch?v=BDCpRuaH4jg

You must rip the drivers of the bad side with the set working .
A week ago I´ve fixed one 40PFL7606 with that exact fail.

[edugimeno]

Re: Philips 37PFL5603D. Image fades out slowly

I don't thins my TV relates to this issue. This is not half a panel, or a stright line or so.
In my case the screen starts ok, sometimes a little darker than usual, and then gradually, from a side or a corner, it starts to wipe, or fade, to black, wiping the whole screen slowly until it all stays not 100% black but very dark, sometimes flickering a little.
I will ask my friend if the screen did it again, after we replaced the main board, I pushed all the boards and specially the Tcon and it kind of returned to normal, I would expect that it will eventually get bad again after it heats up.
If it happens again I will take a video, I need to determine whether it's the panel or the T-Con

[dick_barton]

Re: Philips 37PFL5603D. Image fades out slowly

I have a Samsung set here and it does almost exactly what you describe.
If I turn it on and off 20 or 30 times I can get it to give me a good picture. In between I'll get a blank white screen with black blotches that grow in size quite quickly. I fairly certain its a panel or COF fault so it just sits here for spares.

[edugimeno]

Re: Philips 37PFL5603D. Image fades out slowly

I called the guy today, he said the TV has been working 7h/day since we swapped the boards, 3 days ago. I still want to believe it is a bad solder in the T-Con board, we pushed hard on this board and since it all seems to work. I don't think a Bad panel would improve by pushing it

[arenat]

Re: Philips 37PFL5603D. Image fades out slowly

The 40PFL7606 I´ve fixed behave exactly as yours . Usually touching the culprit the problem came and go .The T-CON can´t do that .

[edugimeno]

Re: Philips 37PFL5603D. Image fades out slowly

If you mean the effect in the video you posted before, the issue in this TV is not by far related to that one

[Moreno83]

Re: Philips 37PFL5603D. Image fades out slowly

This is 100% NOT a bad t-con! Bad t-con will show negative colours not a washed out black screen.

The problem you describe is a panel problem. I had 2x 37PFL8404 , it is a philips with ambilight.
Both did the same. Turns on fine with a blue philips screen and suddenly it looks like a curtain that closes. Washed out screen.

What you can try is to squeeze the bezel top left or right and you will see it gets better again. Only solution is to put something between the bezel and the panel.

Sorry , these models are know for panel problems.

[budm]

Re: Philips 37PFL5603D. Image fades out slowly

Panel problem.

[edugimeno]

Re: Philips 37PFL5603D. Image fades out slowly

Moreno83, looks like your problem does relate to mine!
What do you mean by putting something between panel and bezel? Something like what? On what side? If you could please elaborate
The guy keeps saying the TV seems ok now after we worked on it some days ago. We squeezed every part of it looking for a board that would be affected, I ended up believing it was the T-Con board as we pushed hard on it

Thanks!

[Moreno83]

Re: Philips 37PFL5603D. Image fades out slowly

When you pushed on the t-con the small panel board probably moved. The tabs are connected from the panel to the t-con.

When the problem gets back you need to put something between the iron bezel and the small boards from the panel. Look on youtube for tab bonding repair. There is a video by Norcal.

[Andrew F. Ali]

Re: Philips 37PFL5603D. Image fades out slowly

[QUOTE=Moreno83;830018]When you pushed on the t-con the small panel board probably moved. The tabs are connected from the panel to the t-con.

When the problem gets back you need to put something between the iron bezel and the small boards from the panel.

When the TV is showing good picture measure these voltage test points and record them on paper:
1. Vdd (Vlogic, Vddd)
2. Vda (Vs, Vsource, Vdda, Avdd)
3. Vgh (Vgon, Von, Vddg)
4. Vgl (Vgoff, Voff, Veeg)

While the picture is fading or when it fades re-measure these voltages again and compare them with what the original readings were.


You would see some difference. Trace that voltage line on the T-CON Bd. and it may go to a transistor out from an IC.
Insert a thin plastic pad or strip or any insulating material to isolate the Source PCB (long PCBs the T-CON connects to) from the Panel metal shield.

If you replace the T-CON Bd without putting the insulator strips first in place the new T-CON Bd will be damaged like the old one.

[arenat]

Re: Philips 37PFL5603D. Image fades out slowly

If you mean the effect in the video you posted before, the issue in this TV is not by far related to that one

I´m talking of effect you described in the first post . The video is only to show where the tabs are located . You must look at the sides of the panel , could be three or four tabs at each side , rip off all the tabs of the side where the fail begin .Those are NOT the tabs who are located in the upper or bottom side of the panel .

[Moreno83]

Re: Philips 37PFL5603D. Image fades out slowly

As Arenat says , this is your final option. So first try to see if you can "fix it" with the tab bond issue. If not remove the 3/4 tabs on the SIDE of the panel that is causing the issue.

So when it happens , see where it started. Left or right side of the screen. Again this is your final option...

[Davi.p]

Re: Philips 37PFL5603D. Image fades out slowly

The methods adviced here for the panel fault i think are related to the case where only one side or little more gets darker but here the whole screen it is, so just to be sure it is not the backlight you have to watch with a flashlight the entire screen, if you find the image all there when fault is present then it can be something in the backlight circuitry, maybe some solderings, if not is in someway a problem of panel matrix drivers, the bad tab's traces that the best way to fix them without switching off all a side's tabs is a jumper wire between long board to the 1st side tab.

[edugimeno]

Re: Philips 37PFL5603D. Image fades out slowly

Ok, the guys keeps saying his TV is working good now, after me moved some stuff inside the other day.
Yes I hadn't thought of a backlight problem, I will check that out too if the problem comes back.
Doesn't pulling/breaking the flex wires affect the TV in anything? Seems werid to me that those flex are there for nothing

Thanks everyone