LG 60PB5600 Turning Off

[heavymachines]

Re: LG 60PB5600 Turning Off

Actually, upon looking at the back of the TV, it looks like the logic board actually received power from the main board and there is no direct power cable from the power board to the logic board.

Noted humm it looks like it would have to get it from y. Where is tom lol he would know for sure.

[ShaunM]

Re: LG 60PB5600 Turning Off

Is it possibly a power board issue or would you still lean towards ZSUS.

As mentioned before, the power will stay on if the YSUS is disconnected but since the YSUS draws power from the ZSUS I am unsure if it woulkd be the power board screwing up when the ZSUS is trying to draw more power to feed to the YSUS or if the ZSUS is getting enough power but the components feeding the power to the YSUS are bad?

I am fairly certain that the YSUS and Y-Buffers are good because they have been switched out twice with same error. As well, these were bought new from Sears and were not in used condition.

[dick_barton]

Re: LG 60PB5600 Turning Off

If you search the forum there are a quite a few threads on how to test the power supply on its own using light bulbs as a load.

This was posted some time ago. Don't take any notice of the pin numbers on the drawing because they are unlikely to match the Vs pin numbers on your connector. It's to give you an idea.

[ShaunM]

Re: LG 60PB5600 Turning Off

Thanks. I will search and see if I can find that specific thread.

[ShaunM]

Re: LG 60PB5600 Turning Off

Thanks for all your help. I thought I checked all the voltages but it turns out that I missed the upper connection to the ZSUS(the one you think I would have checked...lol). All the voltages to the main board were spot on but the voltages to the ZSUS were practically non-existant.

Chalk it up to my kids interrupting me when I was doing the voltage checks and my forgetfulness of what I had left yet to check.

[dick_barton]

Re: LG 60PB5600 Turning Off

So you're up and running?

[ShaunM]

Re: LG 60PB5600 Turning Off

I believe so. I just bought a power board from Ebay. It is used but the seller has a great rating. I guess I will sell my other boards in "as is" condition for like $40 each since there seems to be lots of people repairing these boards and selling them for at least double that. Plus, for all I know, the YSUS boards and Y-Buffers are probably good since it turned out to be the power board.

Once again, thanks for your help. It is greatly appreciated!

PS. I would be more than happy to submit a donation for helping this forum.

[dick_barton]

Re: LG 60PB5600 Turning Off

There is a donate page for people interested on the index page.

https://www.badcaps.net/forum/index.php

[ShaunM]

Re: LG 60PB5600 Turning Off

Found it and done. Thanks again.

[ShaunM]

Re: LG 60PB5600 Turning Off

Well, I am back. I got the power board today and the same issue is occurring. The TV powers on and as soon as sound comes through the speakers it automatically switches off.

I am at a loss. I have replaced the power board, YSUS board and both the buffers???

Any suggestions or ideas would be greatly appreciated!

[dick_barton]

Re: LG 60PB5600 Turning Off

Go to the power supply board, power off, and measure the resistance between VA, VS, 5V, 15V (and whatever voltages are given on the connector pins) with respect to ground and please list the results.

[ShaunM]

Re: LG 60PB5600 Turning Off

all the pins are reading 1(is that not open loop) with the exception of the grounds at .6

[ShaunM]

Re: LG 60PB5600 Turning Off

Same thing with a second multimeter but the grounds come back as .2 rather than .6

[ShaunM]

Re: LG 60PB5600 Turning Off

When I have the board plugged in I get 5.2 on the 5V but all the other pins have no voltage. The connector going to the main board seems to have proper readings though.

[dick_barton]

Re: LG 60PB5600 Turning Off

all the pins are reading 1(is that not open loop) with the exception of the grounds at .6

Do you do the resistance check with all the boards plugged in?

What is the maximum voltage VA & VS reach immediately after switch on but before the set switches off and do they match what's given on the label on the back of the set.

[vinceroger69]

Re: LG 60PB5600 Turning Off

could it be a bad buffer board like in this video i know its not the same model but looks like the same set up board wise
https://www.youtube.com/watch?v=z3dxCJ3CaTs

[ShaunM]

Re: LG 60PB5600 Turning Off

I was thinking that maybe the power board I got from Ebay was bad but the seller has an excellent rating and has been in the TV repair business for years. He asked me to unplug the both power cables(the one to the ZSUS and the other to the main board) and verify that the board has around 200v on the vs. Once I unplugged everything I did get around 200V as he said should happen.

I did notice that there was only one click when I plugged in the tv to do this test where there is usually 1 and then another click a second or two later.

I did test both y-buffers and there was no beeps so the ICs all seem good.

[heavymachines]

Re: LG 60PB5600 Turning Off

So you're getting both va and vs voltages from power supply with y and z disconnected right?

[ShaunM]

Re: LG 60PB5600 Turning Off

Yes, with the YSUS disconnected from the ZSUS. The YSUS gets power from the ZSUS on this model. But when I power on the TV with the YSUS connected I get no VS.

I did not think it would be a YSUS issue because I have replaced it twice with a new board from Sears. The second time is when I replaced the YSUS with the Y-Buffers and I tested the Y-Buffers and there are no beeps when tested.

That is my confusion. If the YSUS was originally shorted by the Y-Buffers then why would it short out again if the newly installed Y-Buffers(installed at the same time as the new YSUS) are proven to be fine?

[ShaunM]

Re: LG 60PB5600 Turning Off

Maybe Sears sent me a faulty YSUS?