LG 50PX2DC-UD No picture/sound

[raider08]

Re: LG 50PX2DC-UD No picture/sound

Just to add for those curious with the case: we (Coppell TV Repair) received the YSUS board referenced in this case and it tested out fine.

It's fairly rusty, but it worked in our set.

So the hunt continues.

It bothers me that disconnecting YSUS from +5V makes the set stay on.

Can you then turn it off at will?

You do not have the YSUS board now and without it the ZSUS board could not be connected.

You say that the TV comes on and stays on.

Can you , then, try to supply signal to one or more of the inputs and then flip through the sources (be it with a button on the case, be it with a SOURCE/INPUT button on the remote) until you get audio out of the set?

If I unplug the +5v connector and power it on with the power button on the TV(I dont have the remote) it will flash green like 15-16 times then go to solid green on the standby light. I remember not being able to shut it back off without unplugging it.

When I get home I will try hooking up a dvd player or something to it and try to get sound out of it.

Thank you

[dkneyle]

Re: LG 50PX2DC-UD No picture/sound

Well, at least we've eliminated a commoin source of problem with these sets. And for less cost that buying a secondhand Y-Sus and finding that was never the problem. I think we are back to the power supply. Try the techniques mentioned by the Coppell Repair guy.
Then if I was you I'd go back to the power supply again. I'd be changing out all those electros with upgrades to start with. They might look OK but as many here will atest to, they don't have to look bad to be bad. They are sandwiched between some pretty big heatsinks that could simply dry them out. I see they appear to use Nippon-Chemi-Con capacitors (at least on my board). From a quick search around I don't see them on the "bad" list, but I can stand to be corrected.
Again, if I was you, (after following Coppell's tips) I'd then take my meter on diode-test function and run it over all the active devices on the board. Look for any semi-conductor junctions that don't appear to behave as expected. Especially shorts across junctions or open circuit regardless of polarity of testing. My experience of doing this type of in-situ testing usually shows up faulty semiconductors which can be more acurately confirmed by removing from the board and comparing with a new device.

[dkneyle]

Re: LG 50PX2DC-UD No picture/sound

If you go to the popular auction website and put "Repair Kit, LG 50PX2DC-UD" into the search bar you'll find electro repair kits for the power supply selling for about $18. The fact that the kits are out there suggests that there is an issue. Time to practise your soldering skills methinks! By the way, it is identical to my power supply board.

[raider08]

Re: LG 50PX2DC-UD No picture/sound

Alright, sorry for taking so long to respond. I plugged a dvd player into the back of the TV while it was playing music. I pressed the volume up key multiple times and then slowly pressed the TV/Video button(probably 15 seconds in between presses). I heard no sound at all.

[dkneyle]

Re: LG 50PX2DC-UD No picture/sound

Where are you at with it? I gather you have put your (now diagnosed good Y-Sus board) back in? Have you decided to take a stab at replacing the electros?

[raider08]

Re: LG 50PX2DC-UD No picture/sound

I've been super busy lately since its spring training time for baseball, working 80+hr a week.. i haven't been doing much with the TV.

Coppel TV called me yesterday and we talked about the TV and what the next step should be. I have to check some voltages when I get a chance, maybe tonight. I just payed to have the ysus shipped back.

Just a plug for Coppel TV Repair, he is super knowledgeable about repairing TVs, and was able to explain why my TV is acting the way it is. He explained it in a way that I could understand.

I really appreciate the help from this forum and Coppel, without your guys help this TV would of just got thrown away.

[raider08]

Re: LG 50PX2DC-UD No picture/sound

Haven't made any real progress, other than receiving my ysus back from Coppel. I've been busy with some personal life issues lately so I haven't had any time to mess with it. I will update this thread as soon as I proceed to the next step.

[dkneyle]

Re: LG 50PX2DC-UD No picture/sound

In your own time. Remember, it's only meant to be a hobby. Obviously there are other priorities in life. As you say you are going to do, just post a message when you go through the next steps.

[xxkindoruxx]

Re: LG 50PX2DC-UD No picture/sound

i can see its been a couple of years since last post but out of curiosity did you ever get your issue fixed? is the tv working again? im currently having the same issue and would like to figure this out