MLD Back layer jumping?

[coolwavepic]

Hey guys I have a G23 MLD monitor where the back layer starts to jump once in awhile. Has any seen this happen and know what the cause is? Cable issue? Video card? AD board?

[Stayouttadabunker]

I've been pulling out the brainboxes a lot the past couple of weeks, and I noticed sometimes the background LCD slightly darker and with a "blue-ish tint".
I haven't been putting the cover on the brainbox, because I've been digging in the brainbox, and changing stuff.
So the DVI connectors have been getting pulled and pushed on a lot as well.
I decided to spray the video connector pins with some de-oxidization contact cleaner.
It didn't do anything.
With the cover off, I pushed down and left-wards on the top of the video card towards the fan side, or right-side of the cabinet.
I only pushed on the green pcb part of the video card...not on the cooling fins.
Sure enough, the blue-ish tint went away instantly! and I had a nice looking, bright monitor screen again!
Move your video card around a little...see if you can get the LCD to react?

In restrospect, I believe the springy contact pins down inside the video card connector have been pressing against video cards for a long, long time.
These tab spring contacts down in these long black plastic PCIe slots, are getting weak from aging, I'm sure.
Some AVP's I'm playing with are dated around 12-13 yrs old now.

Maybe see if you pull out on them a little tiny bit so the springs push harder against the gold video card tabs?
I just checked...no way you can do that...lol
What are they called PCIe slots?
I've notice that these spring contacts, are weak on the Interface cards that the bill validators push onto as well.

[coolwavepic]

and....... THE BACK LAYER IS OUT! 

[Stayouttadabunker]

Lcd power inverter ballast die out?
If so, shine a flashlight on the screen at different angles in a darkened room....
If you see symbols, then the video signal is going thru ( which is a good thing) but either the ballast is shot or the fluorescent tubing that lights up the display glass.

What strikes me is that background is very white...it's not black?
No video signal getting thru?
Flashlight will tell ya.

[coolwavepic]

It’s all white.

[Tilt]

Ugh.  You've probably already done the basics, but make sure all cables are tight.  The ones from the MPU to the monitor, and also the loop cable on the back of the monitor.  If all that is good I'd be looking at the A/D boards as the likely problem, with the panel itself also a possibility.   Both the inner and outer layer use the same LED backlights, so that wouldn't be the problem.  To disassemble the monitor you have to remove it from the door which isn't too difficult, but you have to be careful that you don't drop it or let it slip out of the door frame.  It comes out the front with the bezel on it too. 

Once you get it out and the back cover off you will see the two AD boards, you can swap them around and see if the problem moves to the outer panel.  If it doesn't change try swapping the panel LVDS cables around at the top of the monitor and see what happens.  Good luck!

[Tilt]

I found a few pictures of when I changed the inside LCD panel on mine.  Here's one with the back cover removed.  The AD boards are on the bottom left and right.  I forget which one is which, but you can follow the LVDS cable to the top of the monitor and figure that out.  If you have any noisy or non-working fans now would be a good time to replace them too so you don't have to do it again later.

[coolwavepic]

TILT that is some awesome info! Thank you for the info!!

Are both AD boards the same model? I assume so as they look identical.

Also note in my picture, the white area looks like a "burn" pattern on the left side. That is not my camera playing tricks.. You still think its the AD baords?

[Tilt]

It's a little difficult to see in the picture, but I think I see what you're talking about.  I changed my inner panel out because of that.  If I left an idle game image up for 10 minutes or so and then switched to another game you could see artifacts from the previous game in the rear display.  Depending on what games you switched to and from would determine how visible it was.  I think your shaky and then gone image is a different problem though. 

I didn't have a need to swap my A/D boards around, so I didn't and can't say for sure, but I believe they are the same and interchangeable. 

I made some videos of the process of getting the monitor out of the door and disassembly that I could try to stitch together (or upload multiple parts if I can't figure how to do that) and put on Youtube or something or you if you think you want to try disassemble it.