Philips 52PFL5704D/F7--backlight, no picture

[bdl1989]

One minute it's working--then I turn off, leave for 5 minutes, and turn it on to no picture. The backlight works, but there is no picture. Nothing--can't change input or bring up menu. Philips logo does not display on power up. Backlight flashes on, then off, then solid on again (consistent with what happens when Philips logo displayed prior to issue.

Preliminary reading tells me it could be a t con board issue, but I'd like to be sure before dropping $80+. Can you help me out?

[dskall]

Re: Philips 52PFL5704D/F7--backlight, no picture

Need good clear straight on pictures of back of tv with cover off and each board.

[bdl1989]

Re: Philips 52PFL5704D/F7--backlight, no picture

Will get as soon as possible, tonight, hopefully.

[Davi.p]

Re: Philips 52PFL5704D/F7--backlight, no picture

But audio?

[bdl1989]

Re: Philips 52PFL5704D/F7--backlight, no picture

I haven't been able to pinpoint whether or not I have audio yet. We don't have cable, and the only device that was outputting to the tv was a (monitorless) streaming PC.

I am going to try to connect a laptop via HDMI (so I can see what I am controlling) and have it play music as I blindly cycle through TV inputs, and will let you know if the TV outputs sound as I cycle through its inputs.

[bdl1989]

Re: Philips 52PFL5704D/F7--backlight, no picture

So, I was able to confirm that I do indeed have sound, connecting laptop via HDMI. Eventually, I blindly found the correct input, and successfully played audio through the TV.

So, current state:
--no picture
--backlight is very apparently working
--I do have sound

I will get into the back of the TV at first opportunity. It's currently on a mount, and I need a second set of hands before I can proceed.

EDIT: Got the TV off the mount, but my torx screwdriver doesn't fit to remove the back panel screws, need a skinnier one. Will proceed ASAP.

[attainteddragon]

Re: Philips 52PFL5704D/F7--backlight, no picture

from memory they are a t10 piece.

[Davi.p]

Re: Philips 52PFL5704D/F7--backlight, no picture

First thing to control are voltages on tcon

[bdl1989]

Re: Philips 52PFL5704D/F7--backlight, no picture

from memory they are a t10 piece.

Makes sense--one size smaller than the long t15 bit I had, of course

EDIT: Unclear. I have the right size torx head available, as I was able to remove some of the screws. However, the piece that my torx bits go into on my screwdriver is too fat to reach the screws in the narrow channels around the periphery of the TV.

[attainteddragon]

Re: Philips 52PFL5704D/F7--backlight, no picture

i have had that problem before. had to buy a security set as it had a longer handle and was not overly thick.

[bdl1989]

Re: Philips 52PFL5704D/F7--backlight, no picture

Sorry for the delayed reply. By day I am a teacher, who just got through a very busy part of the year. Now I have some time again to try to diagnose and repair, if you'd be so kind as to offer some help .

I've attached pictures of the main board, power supply, and tcon board. What is the next logical step?

[attainteddragon]

Re: Philips 52PFL5704D/F7--backlight, no picture

next thing to do is check that you have 12 volt on the t-con fuse. it is on the bottom left.

[Davi.p]

Re: Philips 52PFL5704D/F7--backlight, no picture

The tcon photo is the only one needed but need to be re done, without your shadow on.. and remove those 2 bottom silicon pads.
If you want to go ahead you can modify the photo with adding of each electrolytic voltage.

[bdl1989]

Re: Philips 52PFL5704D/F7--backlight, no picture

Hopefully this photo is sufficient. Poor lighting in my basement .

[bdl1989]

Re: Philips 52PFL5704D/F7--backlight, no picture

Sorry, I'm not clear on where I should be checking voltages. I can get a multi-meter, and point the leads where directed to, but I have no idea where...

[Davi.p]

Re: Philips 52PFL5704D/F7--backlight, no picture

Do you see those silver cylinders? Them are electrolytic capacitor (EL.CO.) , test the voltage on them (purple band is the negative) and report measurements on the picture using Windows Paint or other SW..