Strange Graphics Mario Bros

[Bi11yJ0e]

Tried cleaning all connections and reseating the chips with no luck. Anyone have any ideas? Still new to this so any help would be very much appreciated!! Thanks.


http://imgur.com/a/p78Op

[Bi11yJ0e]

Just replaced the roms and proms with parts from Mikes Arcade and still no change.

[shuyge]

I'm no expert, but if you're looking at the wonky graphics that are in place of the score, here's what I think.

It looks like an address decoding problem to me.  Either a bad buffer / driver, or a bad gate (and, nand, or, etc) or a bad address line that is causing the cpu
to pick up the wrong data when it tries to fetch the font characters.

Watch all of OneCircuit's youtube videos on pcb board fixes.  If you can't make heads or tails of what he says, you need to send the board to someone who can fix it.

Good luck.

Stan