LG 50PQ10 Probable PS issue.

[Gary_B]

Hi all,

I have a LG 50PQ10 and it just stopped working.

The symptoms are a little different from what I have read online though.

The failure was sudden. We came home and there were NO lights, blue or red and it just acts like its not plugged in. The cord is fine and so is the power outlet.

In a sudden and complete failure like this could it just be a fuse?

Gary

[tom66]

Re: LG 50PQ10 Probable PS issue.

It's possible, but more likely to be a little more complex.

Do you have access to a digital multimeter? Any prior testing experience around electronics?

[Gary_B]

Re: LG 50PQ10 Probable PS issue.

Hello Tom, Thank you for the quick reply.

Yes, I have considerable experience in electronics but none in modern TV's I have a DMM and good soldering tools and skills.

Let me tell you exactly what happened.

My wife accidentally switched off two power bars, the internet box was plugged into one and the TV was plugged into the other. I only realized there was a problem because I couldn't get online. We turned on the power bars but the TV didn't and wouldn't turn on. I tested the power cord and it was OK, I made sure it was connected firmly and tried turning the power on and off many times.

Then I posted on this forum.

The next day we plugged it back in and it has worked perfectly since! It even got an unintentional torture test that night. There was a pretty big wind storm and the power went off and back on again faster than I could get up and switch off the plasma. Then over the next 20 minutes it happened FOUR more times! (I should have switched it off) It has worked flawlessly since.

I suspect it simply needed a power drain after the accidental cut off of power when the power bar was switched off caused perhaps by noisy operation of the switch. But if that is the case shouldn't the FIVE storm outages have caused the same issue?

Still kinda worried that it will give out but I know I can replace the caps and that power regulator and fuse if I have to. So nice that the information is so easily available for this power supply.

So for now I guess it's "thanks but all is well" unless there is something you think I should check or do?

Gary B in BC with LG :-)

[tom66]

Re: LG 50PQ10 Probable PS issue.

There is no reason a sudden power on/off should cause issues. I have done it many times with a lot of TVs with no long term harm. They are built for such fault conditions. However it could be an indication of a developing intermittent fault. Run the set for some time, but if it does occur again, it will not have been anything relating to your failure to unplug the set.

[Gary_B]

Re: LG 50PQ10 Probable PS issue.

So far so good! Thanks!

[dcapper]

Re: LG 50PQ10 Probable PS issue.

I have the same model that acted up the same way. It's probably the Ysus. I checked mine. The fuse is blown and there is 7 transistors showing shorts. Chances are it's just one or two of them. I will pull them and test tonight to let you know what I find.

[Gary_B]

Re: LG 50PQ10 Probable PS issue.

Well this time I am sure I really have a problem. I am also quite sure it is unrelated to the previous non issue. I will post a new thread with various voltages, pictures and such once I pull the back off and have a look but I thought I'd just post a quick description of the unusual symptoms in the hope that somebody will know what's happening from their own experience.

We only use our 50" LG 50PQ10 for watching computer files through HDMI.
I was asleep on the couch and woke to find the TV apparently timed out and off as you would expect after a file finishes playing and you don't shut anything off. The red light was lit and there was no sound. (normal).

I walked up and used the main power button to shut it of then turn it back on again. The light went from red to blue to red to blue VERY quickly (may be normal it always does this now and it's so brief that I am not sure that it didn't always do this) then flashed blue one time then came on steady blue. (once again I am not sure if this is what I always see on power up or not so this may be normal). After the usual delay it clicked normally but there is no picture and it made a sound that starts out high pitched for about one second then drops an octave or two and continues like that forever.

The TV reacts normally to the remote and as I said the light seems normal (I think). It does not turn off or flash any other light patterns. It does the same things exactly no matter if it has been unplugged or if I turn it on and off with the remote or with the power switch. When I play a file from the computer the sound seems normal except for the buzzing.

The sound does not seem to be coming from the speaker, when behind the set it seems to come from the right top corner. The back is still on so it is hard to be 100% sure, it may be coming from top center.

I am involved in a big project for the next 5 days and will not be able to remove the back and check any voltages or anything until Wednesday July 8th. at the earliest.

I just hoping somebody will recognize "LG plasma, normal lights and remote function. Normal click but no picture does have sound with buzzing from upper right" and can tell me what happened.

I will still want to verify with checks but I am hoping for a running start.....

Thanks all, this is a great forum, far better than most and I am into homebuilt airplanes. Those guys are INTO helping!