Philips 52PFL5704D/F7 Sound and Backlight, No Video.

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

That would mean the main board isn't sending a signal some how. You pressed AUTO when you probe one of them?

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

I don't know Tom, what is going on, but I can't see any sinuses or square waives. There is something going on, but it's all concentrated along the horizontal line. No matter what kind of adjustment I'm doing on the scope, can't make that signal to show bigger.
The voltage measured is 14.4V-15.2V on the scope.

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Not shorted, but bad. What that could be, that is the question.

[kevinm34232]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Also you have 12v on at the fuse but no voltage at IC201 right? So it would appear that something on the T-Con is shorted..

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Great. Now I know. Do you see CN2 with lots of little silver dots next to it, below "RUNTK"? Connect the ground probe of your scope to the brown copper exposed to the LEFT of these. Then carefully touch and hot the probe on the dot. Press AUTO on the scope (cheating, but it will work for now.) Do you see anything? If so, the main board is probably sending data but the T-con isn't listening.

If you don't get anything, try the a few other dots until you get something. But if you still don't get anything, the main board is faulty.

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Sorry about that, I have just realized what you were referring to.

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

TOP or BOTTOM? I need to know where the video comes in from the main board to tell you where to probe...!

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Both

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Sorry I'm lost. Which side of the T-con is connected to the main board.... I don't have the time for skype sorry, I am only doing this in my work breaks.

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Tom, I haven't given up on that Sharp TV, I will send you that picture with the scope.
Now this Philips TV takes the whole space on my workbench and I can't work on that one.
How nice it would be if we could help each other through Skype.

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Here is shopjimmy's picture:

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Which end does the main board connect to on the T-con. I'm not sure which end drives the LCD and which end receives the video from the main board.

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Both cables are hooked up to the main board. Not sure what are you asking. The right one goes to the main IC on the main board and the left one goes to a bunch of SMD components.

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

OK which end does video come in? That looks like a dual link (two video streams) T-con.

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Here is shopjimmy's picture.
Kevin, I have just remembered that I have checked the IC201 voltages yesterday and they were all 0V.

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

You have a scope, so post a picture of the LVDS connector on the T-con side and I'll show you where to probe to see if you are getting any differential TX signals for the high speed video (here is where 100 MHz is necessary), that way, you can either eliminate the main board or t-con.

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

I was thinking about that too, but it didn't have enough time to run through the firmware, it didn't have any image when I have turned it on.
When it fully turned on I could hear the movie that it was running previously, so it wasn't doing the update.
Do you think that I should stick the USB stick again and let it run for a while?

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Maybe updated firmware broke it?

[tibimakai]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

My fuses are OK. That's what is weird.
So basically when I got it it showed as right now only backlight.
I have opened it and noticed that both panel ribbons were not in there correct position. I have reinstalled them correctly and the TV run beautifully for hours.
Then I turned it off to insert the USB stick with the updated firmware and the video signal it was gone, only audio it was on.
How come it run perfectly and then when I turned it off and then on the video it was gone? Maybe then something went bad?
I have tried heating the board, nothing happened.

[tom66]

Re: Philips 52PFL5704D/F7 Sound and Backlight, No Video.

Looks like active low PS-ON, that is fine. Some PSUs, especially Samsung, are like that.

12VSSB is for 12V for Small Signal Board, i.e. main board.

Perhaps it failed due to the fuse being underrated?