TV Power Problem

[tech2014]

Hi guys. I have been posting a lot trying to get some help on an LG 60PC1D that has a power problem. I have decided to make a video and put it on youtube just to make it easier to understand what I am doing to troubleshoot. Once it is done I will post the link.

[kasfamily]

Re: TV Power Problem

may be needed Repair Kit, http://www.ebay.com/itm/Repair-Kit-L...-/230878881953

[tech2014]

Re: TV Power Problem

here is the link to the video. I will make more if you want me to.
http://youtu.be/6lR3TKiMytc

[ReeceyBurger123]

Re: TV Power Problem

Ok I have seen the video the pfc seems fine check the voltage going to the relays I will try and find a schematic on this psu.

[tech2014]

Re: TV Power Problem

see video I posted above. i already replaced the main power supply which is the bigger board.

[ReeceyBurger123]

Re: TV Power Problem

see video I posted above. i already replaced the main power supply which is the bigger board.

So you have changed out the main psu, was the fault the same with old one ?

[tech2014]

Re: TV Power Problem

yes same fault. The 5v standby voltage is also wonky, it goes from 5v to 0V and no steady 5v standby .when I test all the other voltages, they all come up for a few seconds then back down to 0v. The relays click on and the RL1 and RL2 both go to about 5v then click again and back to 0V.

I noticed that the new board(actually refurbished) is an earlier version. The old board was made in 2009 and the new one is 2007 and an earlier revision. On the original board, the VS would go up then back to 0v, and the VA was only 0.5V and wouldn't move. With the new board, the VA and VS do go up some then back to 0V.

[ReeceyBurger123]

Re: TV Power Problem

yes same fault. The 5v standby voltage is also wonky, it goes from 5v to 0V and no steady 5v standby .when I test all the other voltages, they all come up for a few seconds then back down to 0v. The relays click on and the RL1 and RL2 both go to about 5v then click again and back to 0V.

I noticed that the new board(actually refurbished) is an earlier version. The old board was made in 2009 and the new one is 2007 and an earlier revision. On the original board, the VS would go up then back to 0v, and the VA was only 0.5V and wouldn't move. With the new board, the VA and VS do go up some then back to 0V.

What are you using to get the psu to start ?
Weird as the pfc seems fine.

[tech2014]

Re: TV Power Problem

I just have it connected to the AC cord and connectors from the ac board to the main board. I am going to connect everything into the tv and make another video.

I would like to test the AC psi by itself without the main board. Not sure if i need a load for it or not. BTW, looked for schematic for the psu and found nothing. The service manual does have a small part but not enough to really help.

[ReeceyBurger123]

Re: TV Power Problem

I just have it connected to the AC cord and connectors from the ac board to the main board. I am going to connect everything into the tv and make another video.

I would like to test the AC psi by itself without the main board. Not sure if i need a load for it or not. BTW, looked for schematic for the psu and found nothing. The service manual does have a small part but not enough to really help.

Hook it up to the rest of the set and test it, im sure that the needs a minimal load to start up fully.

[tech2014]

Re: TV Power Problem

Ok both psu are in the tv and connected to all other boards. Now I get no clicks at all, psu appears dead now. When I remove the main board from the circuit, the tv does come back on but still has fluctuating voltages then back to 0.


Here is link to new video.
https://www.youtube.com/watch?v=O7dSdMR6_Yo

[tech2014]

Re: TV Power Problem

I think I found the problem. When the YSUS board is connected to the main power supply, all the voltage lines drop down and the power turns off. Obviously there is a problem on the YSUS board.

[tech2014]

Re: TV Power Problem

Here is the video for my find.
https://www.youtube.com/watch?v=0jnsY4t2AB8

[tech2014]

Re: TV Power Problem

the 5v line is shorted to ground on the YSUS board. Is there a schematic for this board?

[ReeceyBurger123]

Re: TV Power Problem

Hello sorry I didnt reply it was "bed time" here in england, ok so it looks like the psu did need a load to start it when the ysus is disconnected does the rest of the set start eg backlight tft panel ect ?