Model 40x Wms Dotmation: bad DMD controller dragging game down

[cfh]

I have a Magic Lamp dotmation i was working on.
Game would not boot. Dotmation would go through
it's checksums, but the red LEDs on the front door would
never light. The FAIL led on the I/O board would come
on too. But if i tried the CPU and I/O boards in other games,
and they worked fine. The power supply too was good,
tested in another game.

So i disconnected the power to the DOT controller
board, and the game would boot!

Bottom line: even though the DOT controller board
would "boot" and display the start-up messages on the
DMD, it was somehow dragging down an address or
data line from the serial port connector. Because if
I disconnected the serial port cable, the game would
boot fine. With this cable connected, game would
hang and not boot.

Fix: put in a new DOT controller board, and game
worked fine.

I post this hoping this info could help someone in the future.

[kenokarz]

that will save some time shopping things out