LG 50PH670S no video only audio

[xblood88]

hi everyone i have a problem with this plasma. At any moment the video is no longer visible and only the audio is heard. Is there anyone who can help me? i turned on the tv and noticed a hum on the ysus and the heatsinks are all cold on both ysus and zsus. The voltages vs va are all correct. Disassembling the buffer board there is an integrated in short circuit because it is in continuity. Thanks for the help

[dick_barton]

Re: LG 50PH670S no video only audio

Post some photos of the board and also of the area around the component that is short circuit.

[xblood88]

Re: LG 50PH670S no video only audio

Ok this Is a photo

[dick_barton]

Re: LG 50PH670S no video only audio

In photo 2 you have the cable disconnected. Are you saying that one of the two buffer IC's shown are short circuit.

Can you post a photo of the panel label

[xblood88]

Re: LG 50PH670S no video only audio

I disconnected the flat cable because on the contacts of that flat it gave me continuity so I assume that one of the two buffers is shorted and I tried with the disconnected one if it turned on the screen after which I stopped and asked on the forum

[dick_barton]

Re: LG 50PH670S no video only audio

If the buffer IC is shorted then you will need to replace the circuit board unless you are able to or have a friend who can replace the faulty IC.

With it disconnected did you have a picture with just the bottom missing?

[xblood88]

Re: LG 50PH670S no video only audio

In photo 2 you have the cable disconnected. Are you saying that one of the two buffer IC's shown are short circuit.

Can you post a photo of the panel label

Ok

[xblood88]

Re: LG 50PH670S no video only audio

If the buffer IC is shorted then you will need to replace the circuit board unless you are able to or have a friend who can replace the faulty IC.

With it disconnected did you have a picture with just the bottom missing?

with the flat disconnected I did not get any image, I ordered the spare ysus but I would not want to burn it again

[dick_barton]

Re: LG 50PH670S no video only audio

Can you measure -VY which as shown in the photo. Your meter leads connect as the arrows show red to red, black to black. Be careful not to short the meter lead on the heatsink.

[xblood88]

Re: LG 50PH670S no video only audio

I measure 36/37 v

[dick_barton]

Re: LG 50PH670S no video only audio

It should read 190V. Was the last ribbon cable still disconnected. Can you post a photo of your board. Bright and clear.

Edit
You did put your black meter lead on -Vy and the red meter lead on the +Vy to take the measurement? Your meter leads should be connected to the two points at the same time.

[xblood88]

Re: LG 50PH670S no video only audio

measurements are made correctly and all cables are properly connected, heatsinks are cold

[dick_barton]

Re: LG 50PH670S no video only audio

Had you reconnected the bottom cable that connects to the short circuit buffer and then taken the measurement?

[xblood88]

Re: LG 50PH670S no video only audio

It should read 190V. Was the last ribbon cable still disconnected. Can you post a photo of your board. Bright and clear.

Edit
You did put your black meter lead on -Vy and the red meter lead on the +Vy to take the measurement? Your meter leads should be connected to the two points at the same time.

Photo

[dick_barton]

Re: LG 50PH670S no video only audio

If the bottom buffers are short circuit then I would remove the ribbon cable and make certain that it is clear of any obsticles and then do that check again.

[xblood88]

Re: LG 50PH670S no video only audio

measured even with the ribbon cables of the buffers disconnected and nothing changes

[dick_barton]

Re: LG 50PH670S no video only audio

If that the case then it looks as though there is a problem with the Ysus board.

Wait and see what other forum members can advise.

[xblood88]

Re: LG 50PH670S no video only audio

If that the case then it looks as though there is a problem with the Ysus board.

Wait and see what other forum members can advise.

ok thank you very much I have already ordered a ysus to replace but I would not want to burn it because the buffer board is shorted

[xblood88]

Re: LG 50PH670S no video only audio

you know what transformer this is because it's broken

[dick_barton]

Re: LG 50PH670S no video only audio

Why do you think the transformer is broken.?

I think it's the one that produces the -Vy but I'm not 100% exactly sure.