Tech Help: Scan Lines in a DMD

Black Matrix

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Hey all,
I hope this is the right section, but I didn't see Technical Section for pinball machines. My question is this: Has anyone here ever seen horizontal scan lines move from the top of their DMD display to the bottom. Sorry I don't have pics, but if you've ever seen a tube TV that was being recorded by a camcorder, you would see a horizontal scan line pass from the top of the screen to the to bottom then start back at the top. Same thing looking at a TV with your cell phone camera. Anyways, I have a similar thing going on with my Scared Stiff pin. The DMD was replaced within the last 5 years and has hardly any hours one it. I swapped my old DMD back in and its doing the same thing. Some tech friends suggested that its probably the caps. And looking in the back box, i see two boards that use quite a few filter caps. So does anyone know of anyone selling a cap kit for WPC pinballs. Its almost like the image has an AC ripple, but one of my tech friends said the DMD technology was fairly immune to that and the problem was a new one on him. ANY suggestions.
Thanks in advance.
 
Debaser mentioned he had to fix a CV with a similar issue and that it was indeed a bad filter cap. hopefully he can chime in as to which one... I just noticed my T2 doing it slightly as well.

Ground bar hum sucks
 
Hv dmd pcb

The HV DMD pcb is an overlooked bugger that needs attention just like an arcade monitor chassis. I'd bet yours has never been rebuilt and is a bit toasty.. Pull it out and flip it over, look for burnt traces and cooked trannies..

I rebuild ever HV pcb in any pin that I buy now.. Kit is cheap and greatplainselectronics.com has them usually..
 
Just picked up one of these:
http://www.ebay.com/itm/200795638428?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Not sure if I will have to find the caps somewhere else. At least, I assume this board has some filter caps that wasn't mentioned in the kit. Anyone have a link or list for the caps used on the 2 boards in a WPC pin that has the large filter caps. Save me some time to have to pull the boards and look at to figure it out the hard way.
 
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