RE: Testing Cinematronics CPU's

> ----------
> From: Matt Rossiter - Verio Southern
> California[SMTP:matt@rossiters.com]
>
> I've been trying to think of some methods for troubleshooting
> Cinematronics CPU cards that would be fairly easy to follow - so that
> non-electrical engineer type people like myself could fix them without
> feeling frustrated. - then document the procedures. I've already got the
> basic ones down - (check reset pins, check data lines, crystals, verify
> roms are good, etc.)
>
>
> Just some ideas - Anyone have comments on this?
>
>
I've been wondering about making a small change to the monitor.
Namely, putting a pull-up (or is it pull-down) on the MSB of both DACs.
Whichever way is opposite of the rest of the bits. This should result in
the
beam being centered with no input signal instead of being fully deflected
to the corner and popping the breakers (after stressing the deflection
transistors, which only take about 3 cycles of this before dying).

Is my theory sound?

Brendan Keith
brendan.keith@wilcom.com
Received on Thu Dec 31 01:39:34 1998