Retro addons: Big box o’ SCSI part 2

In my previous post I mainly focused on the Cumana proTeus drive. Today I’m going to turn my attention to the SyQuest 88MB drive.

About the SyQuest drive

SyQuest created removable media hard drives, you might think of the Iomega Zip drive when you think of these, but SyQuest goes back further. When I was younger I had a SyQuest EZ135 drive which, as the name suggests, uses 135MB cartridges. I thought this was going to win over the Zip drive a the time. I was of course, very wrong, and ended up with a couple of Zip drives by the time I was in university.

The drive inside this SCSI box is an SQ5110C, which takes these huge cartridges.

The disk cartridge contains the hard disk platter and the heads are in the drive. It should carefully spin up the disk and release the heads. Upon hitting the eject button it will retract the heads, spin down the motor and then release the lever on the right of the drive. Pushing this will eject the disk.

Testing the drive

I inserted the cartridge into the drive, expecting a familiar hard-drive spinup noise, but nothing happened. Just a flashing sequence on the drive, four green flashes followed by four amber flashes. I then found this website which has a table to decode the error. This indicated a motor problem (I kinda figured that anyway).

Disassembly

First of all I removed the PCB at the bottom. This is just a case of removing the screws and carefully disconnecting the two cables as you remove the PCB.

Nothing obvious here, along the bottom edge of the second photo you can see a 3-phase motor driver. My guess is that or the motor itself has failed. I opened up the top lid to make sure the motor was free-wheeling fine and nothing would be obstructing it in there.

All looking nice and clean in there too. There is a decoupling capacitor need the motor driver IC so I checked that and it was well within spec.

I reassembled the drive and plugged it back in on the off-chance that me free-wheeling the motor has freed something up.

Some hope?

Upon powering up and inserting the cartridge I started hearing the slow sound of it spinning up the drive! It took probably 20 seconds to get up to speed, made a sound like it was releasing the heads, slowed down again, spun up again and retried. This procedure happened several times and then the drive spun down completely. A new flashing sequence happened, eight green and eight amber. Nothing in the diagnostics site about this!

I ejected the disk, reinserted and tried again. The drive motor has returned to a non-spinning-up state with the original flashing sequence.

Conclusions and next steps

The motor is a 3-phase motor which, my guess is that one of the phases of either the motor or the driver is shot. This might explain why even when it did spin up it took a long time. The motor is pretty much irreplaceable. As for the driver chip, it is no longer manufactured and expensive to obtain, even for a used one.

I’m therefore admitting defeat with this drive. It is better-off in the hands of someone who has the parts to repair it, and I’ll list it on eBay as faulty with a full description of the fault.

I really am beginning to think that this case is cobbled together with drives that no longer worked. My hope is that the DDS3 drive will work, and I’m pretty sure I can fix the proTeus drive.