philpem
Experienced Member
Hi all,
I'm trying to fix a Shugart SA405R full-height 5.25in drive.
Failure symptoms are that the drive selects and the main motor runs, but the drive will not seek.
I've already replaced the ULN2803 with no change to the symptoms (the new ULN2803 now gets a little warm).
The head stepper motor has about 60 Ohms between the coil ends, and about 30 Ohms between either end and the common (5th pin, black).
Does anyone have a service manual or schematic for this drive? The main PCB is a "25235-3 2332", which isn't in any of the Shugart manuals I found on Bitsavers.
I figured it was an SA400 variant and that seems to be partly true in that the general wiring is similar -- but the designators and pin wiring are very different.
Cheers
Phil.
I'm trying to fix a Shugart SA405R full-height 5.25in drive.
Failure symptoms are that the drive selects and the main motor runs, but the drive will not seek.
I've already replaced the ULN2803 with no change to the symptoms (the new ULN2803 now gets a little warm).
The head stepper motor has about 60 Ohms between the coil ends, and about 30 Ohms between either end and the common (5th pin, black).
Does anyone have a service manual or schematic for this drive? The main PCB is a "25235-3 2332", which isn't in any of the Shugart manuals I found on Bitsavers.
I figured it was an SA400 variant and that seems to be partly true in that the general wiring is similar -- but the designators and pin wiring are very different.
Cheers
Phil.