LG 50PC3D shuts off... bad caps?

[tom66]

Re: LG 50PC3D shuts off... bad caps?

It could potentially be dropping out very quickly, so quickly your meter cannot see it. Do you want to try the fix anyway? It might solve the problem. Post a picture of the underside of your power supply.

[akk944]

Re: LG 50PC3D shuts off... bad caps?

Is this picture good enough? My multimeter is digital so I see what you're saying. The fix can't make the problem any worse right? Is there anything else that could be the problem? Let me know. Thanks

[tom66]

Re: LG 50PC3D shuts off... bad caps?

It can't make it any worse, but I'm not certain it's your problem. It is worth a shot.

I've marked where the solder should go. However, before you bridge these, can you get the part # of the devices that these solder joints connect to?

[akk944]

Re: LG 50PC3D shuts off... bad caps?

I think they are NEC 2571sk621. should i go ahead and solder?

[tom66]

Re: LG 50PC3D shuts off... bad caps?

Yeah, give it a shot. The C-E of the transistor is on the side I've marked (pins 4/3) so that's the correct place to bridge.

Datasheet:

[selldoor]

Re: LG 50PC3D shuts off... bad caps?

while your there can you have a look under the glue blob looks like something hot under there
Also just to the right of that and up there are three traces with soldersplatter on check it is not bridged.There are also a few odd looking joints but test the fix first.

[akk944]

Re: LG 50PC3D shuts off... bad caps?

I see the glue obviously, but I don't see the splashes of solder you are talking about. Where exactly is it. Should I just peel the glue off or should I warm it up some how.

[selldoor]

Re: LG 50PC3D shuts off... bad caps?

glue you may have to heat it its pretty grippy stuff.
It could be a spacer so will need to go back on.
Two pics one shows 3 areas which might be solder or could jsut be the picture.
The other shows some very close joints that may need looking at

[akk944]

Re: LG 50PC3D shuts off... bad caps?

Ugh, the bridge didn't work. I checked a few of the joints that you pointed out and it's just the way the camera took the picture. What's the problem? I did notice that there seems to be solder "missing" above to the left of where I did the bridge. Does that need solder? Also, I did see a place where the the solder for one connection is touching another. I don't know how solder would go missing or short out with another in the first place, but I'm just pointing out what I see. Any ideas would be appreciated! Let me know. Thanks

[tom66]

Re: LG 50PC3D shuts off... bad caps?

It still shuts off? Damn - I was hoping it would fix it. Next test - try unplugging the side console buttons and see if it shuts down still. Stuck button maybe?

[akk944]

Re: LG 50PC3D shuts off... bad caps?

Here's a pic under the hot glue... I don't have a remote so how would I test that?

[tom66]

Re: LG 50PC3D shuts off... bad caps?

Here's a pic under the hot glue... I don't have a remote so how would I test that?

Turn it on and unplug the connection I guess - the TV might remember the power condition if you unplug it and plug it back in?

[selldoor]

Re: LG 50PC3D shuts off... bad caps?

Here's a pic under the hot glue..

Looks ok - a factory fitted tweek

I did notice that there seems to be solder "missing" above to the left of where I did the bridge. Does that need solder? Also, I did see a place where the the solder for one connection is touching another. I don't know how solder would go missing or short out with another in the first place

Youd need to mark on a pic for use to spot it - You have not had the set from new so anyone could have worked on it before, there are a few more dubious joints with a lot of extra flux, suggests they are not "Factory"

The symptom your set has is indicative of bad joints- comes on gets hot joint expands/moves
tv cuts out. You could try the hairdryer trick at this point - get the set cool then switch on
heat up the board and see if there is anywhere you heat it that causes it to cut out quicker.

If you have a coolant spray you can do the opposite.

[akk944]

Re: LG 50PC3D shuts off... bad caps?

Ok, let me try the switch thing first, then I'll pull out the hairdryer. Can you explain the process to me a little clearer. I.E I'm supposed to heat the top of the board with the tv plugged in or what. Thanks for all the quick responses. Attached picture of missing solder.. or so it seems.

[selldoor]

Re: LG 50PC3D shuts off... bad caps?

"No Solder" I cant really tell what is on the other side of the board may just be a positioning pin for a transformer or heatsink
nothing amiss.

Hairdryer : you said the tv comes on for a while then switches off. If this is due to a component or solder joint getting hot then if you heat it externally the set will go off quicker. So when it has been off for a while turn it on as normal then with a hairdryer just play it on different parts of the power supply to try and get it to switch off. (it may not be the power supply at all - you can try it on the other boards - do not overheat.
When it goes off remember the area you last heated then when it has cooled do the test again but concentrate on the area you thought made it go off. Obviously there is no rule that says it will work at all but many have had success. If you find the area post a picture and we will try and suggest what is the problem.

[akk944]

Re: LG 50PC3D shuts off... bad caps?

Well, which other board could it be. Also, the TV doesn't even stay on for one minute at this point. It would be very difficult to do what you are saying.

[tom66]

Re: LG 50PC3D shuts off... bad caps?

Well, which other board could it be. Also, the TV doesn't even stay on for one minute at this point. It would be very difficult to do what you are saying.

It could be the main board at fault. I also believe this model of TV has a temperature sensor on the plasma panel so if that sensor is reporting an overheating TV it could be an issue. Maybe there's a way to access the shutdown log, if it has one.

[selldoor]

Re: LG 50PC3D shuts off... bad caps?

Sorry I had gone back and read your original post where you said it stayed on a while. In that case can you get a fan or aircon on it and get it cooled down and see if it stays on any longer?

[akk944]

Re: LG 50PC3D shuts off... bad caps?

Oh no problem. Where is the temp sensor? If I knew where that was I could focus the air there... Let me know. Thanks!

[tom66]

Re: LG 50PC3D shuts off... bad caps?

Oh no problem. Where is the temp sensor? If I knew where that was I could focus the air there... Let me know. Thanks!

It's in the most inconvenient place - buried under the main board - on the PDP logic processor.