System 11 LED problem... HELP please.

[Guest]

Archived from groups: rec.games.pinball (More info?)

I have a Jokerz that I rebuild the power supply on and the displays
came up perfect. Then, yesterday, the are "T"'s along the bottom row
of 16 digits. The display works still, it just has this background
issue. Is the glass going bad? Could it be a bad UDN chip on the
display PCB? Any suggestions would be appreciated.

 

[Guest]

Archived from groups: rec.games.pinball (More info?)

Still having this problem. I think it may be a bad 7180. How do I
testthe input/output pins with a probe? It seems like the problem is
on the display pcb, not the CPU.