Mac Classic, Hard Disk damage

You'll love this. Bang it. Try other things first, but seriously, it might work.

The SCSI HD in my centris 650 stopped working one day, and I thought that was the end of the line for that system. So I got the lid off in preparation for parts scavenging, and fortunately got interrupted before even pulling off one connector. On returning the next day to continue the tear-down, I thought "one last chance" and tried powering it up. Nothing. Just the blinking wants-a-floppy icon. In a fit of pique, knocked on the offending HD case w/a screwdriver handle. Suddenly there was the joyous sound of the drive spinning up(which I hadn't noticed was absent due to other ambient noises). Well, the rom had already given up THAT time around, so I pressed the reset, and it booted. Everything was there.

This seems to happen with old disks sometimes, dunno if it's a sticky spindle or a loose connector, or what. Doesn't seem to be the scsi or power cables. Anyway, posting this to spread the word - last ditch - bang on it.

Hey,

That 40MB limitation is incorrect. Depending on what system you use, you could stick a 10gigger in there but all that room is pretty pointless with a Classic. A one or two gig drive will work fine with system 7.0.1. You might consider hooking a Zip drive to the scsi bus and using that if you're queasy about going inside.

William
www.williamahearn.com

The older drives, especially the Quantum Prodrive 40MB and 80MB ones, were notorious for "sticktion" where the brake for the platter drive motor gets stuck after the last power down and won't let loose during the next power up. It's best to do the tap on the side of the drive case, not the top cover. It's best to tap in some way such that the jerk of the tap will move the drive case but the inertia of the platters keeps them in place, kinda the opposite of a gyroscope, and thus helps the brake loosen. I find it's best to do it just after power up so you also have the platter motor trying to spin the platters while you do it.

Check this thread:
http://www.applefritter.com/node/20660

and if you have to replace the harddrive:
http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html#Caution

I've replaced the harrdrives in my Classic II's without taking all the precautions detailed in that webpage, but I don't make any claims to being an intelligent human being, and of course, don't recommend in any way careless recklessness.

The 230Mb quantums get stuck over time. Just get a new gigger drive.