LG 50PC3D shuts off... bad caps?

[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?

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.

[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?

[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?

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?

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

[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?

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?

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.

[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:

[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?

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?

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 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?

I just tried it again and noticed that it even goes down to 4.6x for a brief second, but always shuts off if it goes below 4.74. I was re-reading the previous posts and it seems like I should have seen the voltage drop all the way to 0. Could this still be the problem or should I be looking elsewhere?

[akk944]

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

Okay so i ended up just soldering wire to it and got some results. I did notice a voltage drop before it kicks off, but don't know if it's enough to do it. When plugged in and off, it gets 4.8 volts. High 4.7s when running, but as soon as it goes down to 4.74, it kicks off.. unless the voltage comes back real quick. Does that help diagnose the problem? please let me know. Thanks!

[selldoor]

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

On most sockets you can get the probe down next to the wire and touch the top of the hollow pin in there or there is a hole in the side of the socket you can see the pins through. - easier than wires if you can do that - Id use a ground screw for the black probe.
You may need a helper -Whilst testing get someone to a) plug it in and b) switch it on and note the voltage recorded in both stages and again when it goes off.

[mariushm]

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

Ah that helps... Thanks! so should i just use the first ground below AC-D?

Look on the other side of the board.

If that metal wire (jumper) connects the two GND pins, then you can simply put the multimeter probe on the wire outside the connector.

If that jumper wire is not connected to ground, ignore it.

Either wrap a thin wire around the pins for AC-D and GND or solder insulated wires at the bottom of the board on the pins.

If you go with wrapping a thin wire around the pin, you might find it easier to wrap wire around the two GND pins on the connector on the right.

When you push the connector in the socket, the wires should stay pressed there making contact, good enough contact to make measurements for a short period.

It doesn't matter what GND pin you use, GND should be the same in all connectors.

[akk944]

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

Ah that helps... Thanks! so should i just use the first ground below AC-D?

[mariushm]

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

Solder a thin wire at the bottom of that pin, or just wrap some wire around the bottom of the pin. Or solder the wire on the bottom of the board (on the other side) where that pin is soldered through board.
When you press the connector over the pins it should keep the wire in place.

Hell, you don't even need to solder. If you're careful you can just use an insulated wire, strip a bit at the end, put the wire on the back and use some insulating tape to make the copper from the wire stick over the pin solder, without touching the other pins solder.

That should get you access to the pin. A Ground pad or pin should be available around that connector. Use same for the ground, solder a wire on the bottom of that connector on the other side of the board. Or have a look at where the trace for the GND pins go... it looks like one of those jumper wires in front of the connector is gnd (at least one end terminates right where the GND label is).


No, you probably need to have all the connectors plugged. I don't have experience with this TV but it makes sense.