Chosen Solution
I like tinkering and fixing things but this one has me stumped, I am pretty good with a soldering iron and can lift and replace chips if necessary as I have a heat wand. Yesterday suddenly this TV had no sound, I opened the boy up and traced the speaker wired to a connector with 4 wires, initially I figured this was the issue so took the board out and refreshed the solder on the connections to the PCB, ran an open test and all seemed well with the TV running for 10-15 minutes un-interrupted, I put the wires back into their clips ann secured the PCB with the 2 screws needed, I then ran another test with the TV still open. This time after around 5 minutes the TV started to make a crackling sound with intermittent loss of sound, eventually the sound just went completely, strangely when hitting the power button to put the TV in standby the sound came back for that single moment just before it switched off, turning the tv on again (while the board is hot) just reverts back to the crackling then loss of sound completely. If I let the TV (cool down) I can them probably get another 5-10 minutes perfect sound out of it. Now I am wondering it there is possibly a short in the wires when the tv gets warm, strangely the headphone jack provides perfect continuous audio. I’m not one for buying a new tv when I can repair it myself, but I definitely need some guidance on this one, I’m used to messing with games consoles and pc’s so an HD tv is something different for me and an interesting challenge. Keep up the good work you guys do, any responses are greatly appreciated.
Hi @drunkenninja , I noted that you said that about the headphones audio. The image below may show better what I was alluding to. This is NOT your socket configuration as it is too many connections
(click on image to enlarge fro better viewing) Imagine audio coming into the socket from the audio amp on pins 2 & 6. and it is then sent to the speakers on pins 3 & 7. When you insert the headphones these connections are broken and the headphones connect directly to pins 2 & 6. The contacts on pins 3 & 7 are broken away and there is no audio to the speakers. These contacts may be dirty or there is not enough contact pressure for a good connection when they are closed. So it may be a faulty socket. This is of course if it is wired this way and not where they use a contact in the socket which operates when the plug is inserted to signal the audio controller to switch the audio to the headphones socket
Based upon your description, I would suspect a bad speaker that is causing the audio amp IC to overheat. Any chance you have a set of speakers to use instead of the TV ones? Try that first. If that ends up the same way, change the audio amp IC. That should resolve the problem.
