HD20 Problems

Try:

http://www.mandrake.demon.co.uk/Apple/hd20.html

Phil

Yeah, this is one of the most informative sites on the web. I have gone through the procedures listed there, but to no avail. Unfortunately the HD20 came and went at a time when Apple's answer to everything was "See your Apple Dealer" and was so short lived because the SCSI based Plus came out less than a year later and changed everything leaving the HD20 in the dust (literally). So very little trouble shooting was conducted on the consumer level. The Apple Repair Manual describes take-apart procedures ONLY. So I need more detailed info that only a die-hard, technically inclined HD20 user would know.

I'm pleased that you found my pages helpful. If your investigations into the HD20 throw up anything useful, let me know. If it was my disk I'd give up on trying to recover any contents (most of the software for the Mac 512K is locatable somewhere on the internet, although I'd still like to find pre-1991 versions of NCSA Telnet) and focus on resurrecting it using Apple's HD20 utility or one of the third party tools.

Good luck, 'cos an HD20 is a useful addition to a 512K.

Phil

Are there any physical problems with the drive itself? Is it clean? Are the contacts clean? Is the drive clicking or anything? If there's anything else, it would help to know.

Nope. The drive is fairly clean looking. It spins up in the allotted 15 seconds to a healthy glowing green light on front. When I turn on the Mac, it seems like it accesses the drive several times and then returns the message "this disk unrecognizable do you want to initialize". When I run the HD20 Test utility, in either the normal or "command+D" mode, Everything goes well into the test, then with no strange noises or anything else, it simply stops about 20 seconds after it starts and the log report indicates that there was a disk error "selftest; Stat 5: 000F7DE0 Failed[7]". I haven't yet opened the drive to inspect it, but it may be a circuit board problem, as the power supply seems fine. And unless it's a leaky capacitor or something physical, it may not be repairable (i.e. if it's an IC chip). I presume the HD itself is sealed like a SCSI drive, so if it's not the logic board, then there's not much I can do to the drive. While I haven't tried to initialize it yet, I did try a destructive diagnostic test (cmnd+D) and got the same self-test error. So, I may not be able to initialize and reformat the disk until I figure out why it won't pass its self test. I assume the self test works much the same way the Mac's does when it starts up. If the Mac is otherwise running fine, the self test usually fails due to a RAM problem, or other IC issues and returns an error code. If anybody knows where I can find HD 20 error codes, perhaps I can get to the bottom of this. Thanks!

The fact that it returns an address in the error message indicates to me that it's getting stuck on a bad sector, possibly? Just for fun, maybe try the freezer trick thing.

I have several working Apple hd-20's for sale. make me an reasonable offer. I have the special formatter disk which I will include.