[Coco] calling all MM/1 owners

[George Ramsower]

----- Original Message ----- 
From: "Bob Devries"
>I have a small problem with my MM/1, and I'm wondering if there was ever a 
>fix for it?
>
> When I power it up, the computer goes through its procedure to try to boot 
> from the floppy, and then from the SCSI hard disc. It *always* locks up 
> the SCSI bus at that point, and pressing reset does not unlock it. I need 
> to cycle the power to unlock it. It then usually fires up correctly, but 
> not always.

This smells to me of it possibly being a bad electrolytic somewhere in the 
power supply, either in the main PS or the one on the dard drive(if it is 
seperate). Not being familiar with the MM/1, there could be some filter caps 
on the main board where the power supply connector is.

I would first let it run for a while and then turn it off and start over. If 
it works good upon the second startup, then I would turn it off and let 
everything cool off and try again,, looking at the voltages with an O-Scope 
to look for any noise or ripple on the various voltage lines upon a totally 
cold startup and see if there is a change during those first few minutes. I 
have a CM-8 with retrace wrap-around that (someday), I'll find that 
capacitor and replace it. However, it only take a few minutes for the cap to 
reform after it warms up. I've seen this sort of problem countless times.

George