LG Y-Sus Replacement

[ibanez6]

Hello,

I just received a new Y-Sus and Y-Driver (buffer) board for my LG Plasma (42PG20). Upon removing the Y-Sus board, I noticed there are numerous locations where a sticky grey pad had been placed on the bottom facing the chassis.

The new board shows the locations where to put said pads, but unfortunately the old ones have all deteriorated and have lost their ability to stick.

I was wondering what these pads are actually intended for, and whether I really need to put new ones on this Y-sus board? I figured it might be for insulation purposes to prevent any contact between the TV chassis and the electronic components, but I would think that the board should be mounted far enough away from the chassis that it wouldn't be an issue.

I have attached a couple pictures to show what I am referring to.

Cheers!

[ibanez6]

Re: LG Y-Sus Replacement

Also, I just noticed the sticky about putting model numbers in thread titles. Any way to edit?

[Shinju]

Re: LG Y-Sus Replacement

I wouldn't worry about it, my 60PV450 original boards had this foam on the back and the boards out of the newer revision of the same panel did not and I haven't seen any issues thus far.

If super concerned about it I would just put strips of Kapton tape on the panel under the boards.

[ibanez6]

Re: LG Y-Sus Replacement

Thanks for the reply Shinju! I was able to successfully install the two boards. Now I seem to have another problem.

So to backtrack a bit.. A received this TV from my friend who said it had sound but no picture. This is my first time working on a plasma, so I did my research and started checking voltages. The PSU is putting out proper voltages, but the Y-Sus was outputting some very inconsistent numbers, and almost nothing to the Z-Sus board.

Just replaced the Y-Sus and Y-driver board, and the panel now powers up fine and I can see the menu and what not. However, I am now seeing a new problem on the top half of the screen as seen in the attached picture. Voltages all seem good now.

Not sure which board I should be troubleshooting next. Any ideas?

[Shinju]

Re: LG Y-Sus Replacement

Looks like a failed/failing upper Ydrive buffer to me. LG is very tricky on running half screen in fact quite a few newer PDP LG panels you cannot do it.


Can you post a Full Monte shot of the backside of the panel?

Also one thing to check is to make sure all your connections are solid and all your ribbon cables are seated correctly and inserted all the way.

[ibanez6]

Re: LG Y-Sus Replacement

So I just double checked all the ribbon cables and everything seems to be seated properly. On this particular model the Ydriver is all one board so no upper and lower. And it was one of the boards I just ordered and popped in. Looks brand new actually.

I've attached a couple pics. The first one is an overall view of the back. The second one shows the new Y-Sus and Y-Driver boards I replaced this morning. I also attached a diagram from a training manual I found for this model.

Please let me know if you need anything else.

[Shinju]

Re: LG Y-Sus Replacement

Was the old y-drive board bad?

[ibanez6]

Re: LG Y-Sus Replacement

Well when I first got the TV, it would turn on, and would stay on (blue power light). But no picture. The panel wasn't being energized at all.
So I was recommended to replace the Y-Sus and Y-driver at the same time, as apparently one or the other can sometimes short each other out if there is an issue.
So I haven't tried the original Y-Drive board with the new Y-Sus board.

Would you recommend trying it then? Also, in the diagram it shows a Left X and a Right X board. According to the manual they deal with the following:

"X-BOARDS CONTROL THE VERTICAL GRIDS WHICH DETERMINE THE HORIZONTAL PIXEL COUNT.".

Any chance it could be related to those?

[ibanez6]

Re: LG Y-Sus Replacement

Here is the service manual for the TV if it helps at all:

[ibanez6]

Re: LG Y-Sus Replacement

Well now... I decided what the heck and swapped the old buffer board back in and presto, problem solved! So looks like my supplier sent me a faulty buffer board then. Thanks again for all your help!

[Shinju]

Re: LG Y-Sus Replacement

Cool, I was going to suggest you try your old one again and see. But it looks like you took the initiative and did it yourself!

thanks for the follow up!