I have a MacSE with an internal Miniscribe 8425S 20MB hard-drive. The drive has stopped working in 1990 and it hasn't been touched since then.
The issue is that the drive doesn't spin at all. There is no disk rotation when it boots.
I have opened the drive and both the PCB board and the mechanical internal parts look OK. See attached photos.
I have plugged my own 12V power supply and I see a pick of current around 750mA for half of second and then it goes down to 0. The voltage goes also down to around 10V. And it does it again.
In other words, it seems that the logic board tries to rotate the disk but it's not succeeding. I can manually rotate the disk. The 6-pin white connector on the side of the board looks OK. I guess that it's what powered the disk rotation motor.
I have seen some posts and videos about problems of the little side motor that pushes back and forward the arm but I don't think it's the issue I'm dealing with. My problem is no rotation of the disk.
Any idea or recommendation how to troubleshoot this drive?
(Ideally, it would be ideal to have a working hard-drive to test A/B between the PCB board and the mechanical part. I'm in the Silicon Valley.)
The issue is that the drive doesn't spin at all. There is no disk rotation when it boots.
I have opened the drive and both the PCB board and the mechanical internal parts look OK. See attached photos.
I have plugged my own 12V power supply and I see a pick of current around 750mA for half of second and then it goes down to 0. The voltage goes also down to around 10V. And it does it again.
In other words, it seems that the logic board tries to rotate the disk but it's not succeeding. I can manually rotate the disk. The 6-pin white connector on the side of the board looks OK. I guess that it's what powered the disk rotation motor.
I have seen some posts and videos about problems of the little side motor that pushes back and forward the arm but I don't think it's the issue I'm dealing with. My problem is no rotation of the disk.
Any idea or recommendation how to troubleshoot this drive?
(Ideally, it would be ideal to have a working hard-drive to test A/B between the PCB board and the mechanical part. I'm in the Silicon Valley.)