MX-3640 Blinking display

[xring1958]

We have a machine that was DOA in the customers office. Had Fan noises but no Display. The MFP board was replaced and the display returned.
After that whenever the machine is turned on the Icons on the display flicker after a while the screen stabilizes and no more flicker until it is turned off and on. We have moved replaced every board from a donor machine except the AC Power board including the display with no change. Any Ideas are appreciated.

Thanks in advance.

[mansart]

New SD card?

[driving lots of miles]

I would try SD card first also, and if not that a bad ground somewhere?