More Commodore PET drives - more help?

[Tony Duell]

> 1) Commodore SFD-1001
>    This is the IEEE-488 (PET) single-drive that looks
>    very much like a VIC/C64 1541 serial drive.
> 
>    The drive powers on, and both the POWER and drive LED
>    come on solid RED and stay that way - no other activity
>    is observed - it doesn't matter if the IEEE bus is
>    connected or not, and resetting the IEEE bus (via PET
>    power-on) has no effect. If the PET tries to access the
>    IEEE bus, it hangs, presumably waiting for an acknowlege
>    that never comes (?)
> 
>    It looks like the on-board CPU is not running at all.

I would guess that's likely to be the case (although I've never worked on 
this unit). 

In which case I'd start by checking the +5V power rail, then check the 
CPU clock and reset pins (make sure the thing isn't held in the reset 
state), then see what the aaddres and data lines are doing. 

-tony