I am working on an SE/30 logic board for a friend. I bought the SE/30 in working condition about 1.5 or 2 years ago, and after testing it, "decapped" and cleaned the logic board for storage. Recently, I recapped the logic board and fixed a bad video muxer, but found that SCSI does not seem to work.
The machine itself, after checking out with a known-good board, was delivered to it's new owner, but I still have the logic board.
The symptom is that the machine finishes a RAM check (although it oddly shows an odd vertical pattern all over the screen until the chime), and then begins to blink the floppy disk question mark. With a floppy disk, the machine boots normally. The activity light on both my SCSI2SD 5.5 and BlueSCSI 1.1 DB25 blink once at a regular interval, about once a second or perhaps a bit slower. The LED on each SCSI device blinks continuously until I power off the machine.
The exact behavior can be observed in this video that TechKnight made several years ago.
I buzzed all of the traces going to the SCSI chip (especially to the SCSI connectors), and didn't find any faults. I desoldered the SCSI chip, and found that the traces underneath look very good. Finally, I soldered in a PLCC socket, and tried both the original SCSI chip, and a a SCSI chip off a battery-bombed board. Nothing changes the behavior of the machine.
I would very much like to get this board repaired and sent off to my friend, so he can begin to enjoy is restored SE/30. Any ideas about what might be going on?
The machine itself, after checking out with a known-good board, was delivered to it's new owner, but I still have the logic board.
The symptom is that the machine finishes a RAM check (although it oddly shows an odd vertical pattern all over the screen until the chime), and then begins to blink the floppy disk question mark. With a floppy disk, the machine boots normally. The activity light on both my SCSI2SD 5.5 and BlueSCSI 1.1 DB25 blink once at a regular interval, about once a second or perhaps a bit slower. The LED on each SCSI device blinks continuously until I power off the machine.
The exact behavior can be observed in this video that TechKnight made several years ago.
I buzzed all of the traces going to the SCSI chip (especially to the SCSI connectors), and didn't find any faults. I desoldered the SCSI chip, and found that the traces underneath look very good. Finally, I soldered in a PLCC socket, and tried both the original SCSI chip, and a a SCSI chip off a battery-bombed board. Nothing changes the behavior of the machine.
I would very much like to get this board repaired and sent off to my friend, so he can begin to enjoy is restored SE/30. Any ideas about what might be going on?
