corrupt

I've got a weird problem on my MV1B that I've noticed with the homebrew title Hypernoid, part of the ball sprite is corrupted like this: Some observations: It doesn't always happen, not 100% sure if it's a function of the machine being powered up for a while and something is warming up As...

I'm getting corrupt graphics from a Raiden II PCB. The sprites are bad and there is a blue grid overlay. Any suggestions on how I can fix this? So far I've: Cleaned and reseated the socketed chips Cleaned the PCB Recapped it Checked for bad traces Test Mode screen is completely corrupt: