LG 60PS60 Plasma picture cuts out until power is reset

[ValleyEcycling]

Good day everybody, first off thanks to everyone that has helped me with some other posts. I got an LG 60PS60 TV in today that I recovered from the dump. I plugged the TV in and was amazed that there were no issues with it, plugged it in to my PS3 via HDMI and sat back to watch some Avatar on it as a test run. About 2 hr 30 (ish) into the movie the screen went black. Sound comes through great still.

I turned TV off then back on again and the picture worked for about 20 minutes before cutting out again. A lot of my research has been saying to replace the y-sus board for picture issues, but I am thinking that there would be no picture at all if this was the problem. I will not have a chance to open it up until tomorrow but I am leaning towards a couple of blown caps that would cause this.

Can anyone help point me in the right direction as far as what parts of the plasma I should be checking? Normally i don't even try to save the Plasma TVs we come across but in this case I thought for a 60" TV i would make an exception. I will post pictures of the boards when I open it up tomorrow but if someone can help me narrow the issue(s) it would be much appreciated.

[tom66]

Re: LG 60PS60 Plasma picture cuts out until power is reset

Do you have a digital voltmeter available?
In a dark room, check and see if the slight glow from the panel disappears when the picture goes, or if it stays.
Plasmas are well worth fixing, the PS series by LG is a damn good set. I have a 50PS3000 for repair, nice picture now it's working.

[Shinju]

Re: LG 60PS60 Plasma picture cuts out until power is reset

Hello and Welcome.

Before anyone can help you, You are going to need photos of the unit exposed from the back and a photo for each board as clear as you can. Being that you are an Ecycle place I am sure you have some sort of DMM to check voltages?

When uploading photos please use the attachment feature (go advance it will look like a paper clip for the icon).

Ysus problems are common on a lot of plasma's and LG's and its not just caps. Drop some photos on the group so that members can help you out!

Good luck!

[ValleyEcycling]

Re: LG 60PS60 Plasma picture cuts out until power is reset

Thanks guys,
@tom66: yes I have a DMM to check voltages, and yes the slight glow on the panel stays after the pictures has cut out.

Attached are the pictures I have, my camera is not of great quality so let me know if anyone wants some more zoomed in/clearer photos. After having taken the back off none of the capacitors look visibly blown, but the cable feeding from the power board into the control board on cable ID p200 was visibly loose, and i mean it was on at an extreme angle so the pins on one side were hardly connected.

I will be doing voltage checks today on the cables, are there other areas I should be checking for voltages when i am at it?

[Shinju]

Re: LG 60PS60 Plasma picture cuts out until power is reset

There is a sticker on the back of the panel top left it looks like that has the voltages for VS and VA check those.

Did reseating that cockeyed cable fix anything?

(I'll let Tom66 take over he is much more qualified for Plasma troubleshooting then I ) :P

[ValleyEcycling]

Re: LG 60PS60 Plasma picture cuts out until power is reset

Not sure if reseating cable has fixed anything yet...TV ran for 2 1/2 hrs yesterday before a fault presented itself, currently running at the 2 hour mark but I had to shut it down to check some of the standby voltages. About to run it through another long movie with a timer.

I checked the voltages coming from pretty well every cable on the board, the VA runs at 68v and the VS runs 194. I checked all sets of cables running from the power board for both these settings and other posted voltages and everything is well within the norm range[i think] (ie 68v reads 67.2 - 68.1). Check at both ends of each cable to make sure it was going through cable as well.

The only possible problem i found from testing the voltages on cables is the cable that connects the ZSUS to the CONTROLLER board, from P100 on ZSUS to P2 on the controller, there are 4 pins that are labelled +15V on them and they are all reading 18.1v. Not sure if this is a problem or not, or if they just require a minimal 15v.

I also checked the heat sinks on the SUS boards to see if they have any voltages reading off them (came across that on the last plasma i looked at) but i wasn't able to get any readings from them (so hopefully not an issue).

If the screen does black out again I will do another voltage test to see if there is a drop to one of the sus boards. Any other suggestions on what else to check in the meantime?

[ValleyEcycling]

Re: LG 60PS60 Plasma picture cuts out until power is reset

An update for those of you willing to help me; after reseating the power connector the TV has run continuously for 5 hours without the picture cutting out, currently running an 8 hour session to ensure no further problems.

However, when I started the TV up this morning I heard a loud(ish) buzzing/hum, using a cardboard tube I isolated it to the circled part in the picture below on the YSUS board, after running for 20 min or so the noise has stopped, but is this something I should be replacing to ensure functionality on this TV before I let someone take it home? Or is this a normal occurance in plasma Tvs? (my focus has been soley on LCD and LED TVs so far)

Thanks!

[Shinju]

Re: LG 60PS60 Plasma picture cuts out until power is reset

Is that heatsink looser then the others? how much wiggle room does it have? If you press on it does the humming stop or quite down?


All plasma TV's hum with in earshot of the panel some louder then others, but once you are a foot or so away you cannot hear it anymore.

[ValleyEcycling]

Re: LG 60PS60 Plasma picture cuts out until power is reset

Ok, I was pretty sure the humming of some sort would be normal with the plasma. There is no wiggle room whatsoever on that heat sink, it is well and truly on the board, and no, when the buzzing was present pushing down on the heat sink did not noticably affect the buzzing.
With the back panel off I could hear it from about 3 feet away behind the TV and 2 feet or so in front of the tv, but when I started playing a movie on low volume I really had to strain to hear the buzz.