I have a Macintosh IICi and SE hard drive. My understanding is both are SCSI. I know one of the two is a Quantum P40S (the one from the mac IICi) I also have a PowerMac G4 that works very nicely and has an airport card in it.

The G4 has a PCI SCSI card. It is an adaptec 2930CU scsi card. I believe it came with the G4.

Now I also have a third hard drive. This drive is an old mac SCSI Hard drive, 50 MB I believe. I am not sure what machine it originally came from. I have gotten it to play nice with my PCI scsi card. I connect it using some ribbon cable and the four large pin internal power cable and everything is fine. That is, the SCSI hard drive is not being put external to the computer. Hence, I am confident my SCSI pci card works.

Now when I remove this third, working SCSI hard drive and attach either the IICi hard drive or the SE hard drive, I get nothing. Interestingly, both of these hard drives have a small LED that attaches to the front of the drive. At no point during my testing does this light show any activity. I also do not feel the drives ever spin.

I would guess that there is some power issue.

Would anyone know if there is anything in particular I should be doing to work with IICi or SE SCSI internal hard drives? Are there jumpers, perhaps, that I need to assign somewhere? What about SCSI terminators? Did internal SCSI hard drives require some internal SCSI terminator. I am left confused on this matter because the third, working hard drive, required no special treatment.

Update 1

I have found that internal mac SCSI HDs have a built in terminator ( I guess you can't put more than one on the bus).

From this old Apple support page:

If the Macintosh in the SCSI chain DOES have an internal hard drive, terminate only the other end of the SCSI chain. (All Apple internal SCSI hard drives have built-in terminators).

So this answers the terminator issue. Thus I am still unsure as to why this isn't working.

Update 2

I have gotten a hold of an adaptec 2940UW and the requisite mac firmware. I've also obtained the Adaptec PowerDomain Control program and SCSIProbe 5.1.2.

The hard drive is indeed detected on the SCSI bus of my Adaptec 2940UW. The problem is mounting. I get the following error message from SCSIProbe 5.1.2 when attempting to mount:

Trying Device 1.0.0:
   FAILED: SCSI error: -7932 (2) Sense: 1 (0)

Trying Device 1.0.1:
   FAILED: Logical units not supported

Would anyone know how to interpret these messages?

  • You need to find out which jumpers are needed for termination of the drives. I suggest you go to the manufacturer's web-sites and see if there are any archival manuals for old drives. The third, working HD, may have jumpers set correctly. – IconDaemon Aug 12 '13 at 18:48

Since the old drives aren't spinning up, don't worry about the SCSI card, data cable, or jumper settings; all they should need to spin up is power (i.e. that 4-pin connector). Since the 50MB drive is working off the G4's power connection, I'm pretty sure that's OK... Which leaves problems with the drives themselves.

Many of those older drives were prone to stiction and similar problems. Essentially, the main spindle and platters would get stuck in place, and the spindle motor wasn't strong enough to spin it up. There were a variety of tricks for breaking them free, most of which involved some risk of damaging the drive beyond repair (like tapping the drive juuuuust so, or opening the mechanism and forcing the spindle "by hand").

Probably the safest thing to try would be refrigerating the drives (be sure to keep them dry -- no condensation!), then spinning them up cold. I had the most luck with spinning the drive in my hand -- the trick here is that you want to spin it flat, that is, spin it around the axis of rotation of the platters. If you're having trouble picturing what I'm talking about, don't do it, because spinning it on the wrong axis could easily make things worse. Actually, even spinning it on the right axis could make things worse; I make no promises at all.

It might also help if you can figure out the manufacturer of the other drive. If it's a MiniScribe 8425SA, I recommend a stake through the heart.

  • I need a young priest and an old priest. These are all quantum drives. – emiller Aug 17 '13 at 18:20
  • I agree though it sounds like the HD and nothing with the SCSI mechanism. Your explanation about the drive being unable to spin seems right. I was suspicious about the HD being broken because in past experience, a broken HD always gave off some sort of broken clicking noise but these trouble HDs stay silent - don't even hear things spinning. – emiller Aug 17 '13 at 18:20
  • What do you think about this approach for striction? sentex.net/~mwandel/tech/repair.html – emiller Aug 17 '13 at 18:23
  • That's pretty much the approach I used, although the pictures are slightly off. You want your hand (and hence center of rotation) centered on the axis of the platters; he's holding the drive a the end further from the center (you can tell by the circular pattern in the drive cover). As for whether the drives click when they have problems like this, it depends on the model. I seem to remember the Quantums clicking, but it's been a long time since I worked on any, and I may be thinking of the even older 5.25" Quantums they used in Mac II and IIx's. – Gordon Davisson Aug 17 '13 at 19:13
  • 1
    Addendum: it doesn't really matter how fast you spin the drive, what matters is how suddenly you start and stop spinning it. If you want to get a little more violent (and more risky) you can spin it so one end of the drive hits something (e.g. a tabletop) and stops the spin very suddenly. Also, I preferred to spin them with the power on so if they did break free the motor would keep it moving, but that's only safe if you have long cables (both power & data) available. – Gordon Davisson Aug 17 '13 at 19:22

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