[Coco] MPI problem or ...???

[Robert Gault]

Brian Blake wrote:
> Okay,
> 
> Had a little extra time so here's what I got from the PEEK:
> 
> 126
> 126
> 64
> 64
> 126
> 126
> 126
> 126
> 126
> 126
> 
> I got the same results with and without the MPI plugged in. I think the power supply is the issue. Late last night I woke up and heard a 'humming' sound. After stunbling around for a few minutes, I unplugged the MPI and it went away.
> 
> Anybody know if there's a service manual for this unit? It's a 26-3024...
> 
> Again, thanks for all the help,
> 
> Brian
> 
> 

Looks like the MPI is correctly modified for Coco3 use.

The humming probably is just slightly loose plates in the transformer 
and not a problem.

I'd suggest putting a VOM (or scope) on the MPI 5v line and seeing what 
happens as you add paks. If there is noise on the line or the voltage 
drops, you will have found the problem. If there is no change, more 
testing will be required to find the cause of the problem.