Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

[grimacelord]

Hi guys. Back again, this time with a Phillips plasma HDTV. Symptoms are no picture, but has sound. TV does power on with blue power light and I can hear the relays click and a slight buzzing sound from the Y-Buffer/Main area. LED on Y-Main stays solid while LED marked LED2002 on Main Logic Control board blinks endlessly in no specific pattern.

I have already searched the forum for other cases and have found multiple cases of the same scenario, but sadly, most of those threads never were updated or the repair was abandoned before a solid repair was found.

I found 2 bad caps on the Y-Main and one on the X boards, totalling 3. After replacement, the TV showed no improvement. Same symptoms.

I have also tried unplugging Y/X individually to see if the TV responds any differently and it doesn't. Same symptoms.

I took readings from all of the power connectors on the main power board and all of the voltages are within range according to what is printed on the board, so that seems to be ok. I also tested all of the fuses, and they checked good.

Any suggestions on where I should go from here? Attached are some pics and I can get more if need be. Thanks a lot guys,

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Anyone?

[tom66]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

See if there is a green LED lit on your Y-main, if so this indicates there is a Y-main protection fault.

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

See if there is a green LED lit on your Y-main, if so this indicates there is a Y-main protection fault.

There is. It is a solid green LED. So where do I go from here to determine if it is Y-Buffer or Y-Main or something else entirely?

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

So, I just tested the Y-Buffer board's ICs by following this video: https://www.youtube.com/watch?v=V6hxf9sARMY

None of the ICs had short to ground.

Still stumped on what to check next though

[tom66]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Get this file:
http://www.toms-service-manuals.com/...&Search=Submit

The plasma panel in your TV is made by Samsung, but this service guide was written by Philips, because Samsung refuse to document the repair procedure.

See page 54 as it refers to the protection LED.
Page 65 has some relevant voltage checks.

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Get this file:
http://www.toms-service-manuals.com/...&Search=Submit

The plasma panel in your TV is made by Samsung, but this service guide was written by Philips, because Samsung refuse to document the repair procedure.

See page 54 as it refers to the protection LED.
Page 65 has some relevant voltage checks.

Alright, so after reading through this service manual, I have replaced the Y-Main board. The new board no longer shows the Y-Main protection fault light. I was still not receiving a display, so I took a second look at the X-Main board and found a fuse that was bad. I replaced it with a working fuse. (see attached image for location)

Now, the TV is actually trying to produce an image! I'm getting the snowy-static, but the image seems to be coming in and out. So it will go black and then back to snow/static, and then back in about 2 second intervals.

What should I do now? I'm close!

[tom66]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Can you post a picture of this snowy static? It sounds like an X-main problem if you are getting that.

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Can you post a picture of this snowy static? It sounds like an X-main problem if you are getting that.

I'll try to. I'll probably have to take a video and upload it to YouTube or something because it flashes in and out. So when I first press the power button, I hear the relays click and then the image of the snowy-static appears for a second or two and then it's all black again, but then it comes right back a second or two later and it does this on repeat over and over.

This is the first time I actually got an image out of this TV and it happened only after replacing that fuse I mentioned in my previous post. I also had replaced a capacitor on this board that was visually bad, but that seems to be the only one as all of the other ones look normal (I realize they can still be bad and look normal though).

While I work on getting a video/picture for you, do you have any suggestions on what I could troubleshoot next? I have been following the service manual you gave me and tested the components that they suggested I test in the manual, but all of those seem to be testing fine. I'll repeat it once I get to work just to verify though.

Thanks for all your help!

[tom66]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Verify all the voltages on page 65 of that document. In particular Ve is very important as low Ve can cause a poor image.

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Verify all the voltages on page 65 of that document. In particular Ve is very important as low Ve can cause a poor image.

Alright, here are the voltages that I am reading.

VS: 190-215DCV (This one fluctuates and corresponds to how the TV image comes in and out. So when the image is out, it's around ~190DCV. When the snowy/static image comes in, it's 215DCV. Endless loop of this)

VA: 56-65DCV (Same behavior as above ^ )

VG: 15DCV

D5V: 5.22DCV

5VSV: 5.24DCV

VSND_POS: 17.27

VSND_NEG: 17.27


Here is a short video of the behavior - https://www.youtube.com/watch?v=xku-y-_JmAE

I had to keep my phone somewhat close to the screen so you could see what it's doing. It cycles like that forever and ever.

Any ideas?

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Anyone?

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Verify all the voltages on page 65 of that document. In particular Ve is very important as low Ve can cause a poor image.

Ok. I tested Ve and it reads 114V and the sticker on the back of the panel says it should be 94V. 10v higher than it should be. Also, the TV has stopped flickering like it was and is now without an image at all again.

[grimacelord]

Re: Phillips 50PFP5332D/37 Plasma HDTV - No Picture, Has Sound

Also, I tested all of my other voltages AGAIN and they are all within range except for Ve and 5Vsw on the connector leading to the main board. That pin reads 6.93V instead of 5.3V.

I'm not sure what to do here, guys. Totally stumped. I don't want to start blindly replacing boards and my customer is growing rather impatient with me, but I can't seem to find a solution. Any (more) help would be appreciated before I'll be forced to abandon the project.