HD20 Diagnostics

Markintosh

New Tinkerer
Mar 31, 2023
55
14
8
USA
Hi gang! I now have FOUR HD20's that will not mount on my two SE's & my 512Ke. I've tried System 3.1, 6.0.5, & 7.0 with & without the HD20 Boot floppy (I know my models do not require that, but I had to try every option).

What diagnostic tool(s) can I use to troubleshoot these drives? I do not want to blindly reformat them (assuming that even works) without finding out what is on these units.

All spin up, green LED goes solid. None mount, all Systems give the "Unreadable, to you wan to initialize?" dialog.

I believe I have a SCSI HDD tool, but I figure that will not be applicable here...

Any suggestions are appreciated...

Thanks!

-Mark


PS: "HARD DRIVE" in pic is my internal SCSI 40MB.
 

Attachments

  • HD20 unreadable.png
    HD20 unreadable.png
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Paolo B

Tinkerer
Nov 27, 2021
275
158
43
Switzerland
In the case of the one I have, the HD struggles to spin once powered up. So, it is recognized, but can’t be mounted.
Once it spins, all the rest seems to be OK and the drive can be “used”.
Inside there’s a custom Rodime drive.
However, apart from the logic board, it seems to me very close to contemporary Rodime SCSI. So, it could be that it’s possible to swap the mechanics.
I share some old pics I took a few years ago, comparing the two units.

1684624269227.jpeg
1684624356675.jpeg

1684624393079.jpeg
1684624468203.jpeg

1684624501888.jpeg
 

Markintosh

New Tinkerer
Mar 31, 2023
55
14
8
USA
Wow, that's really cool! I wonder if I'm having power supply/CAP issues? Mine all spin too, bit do not mount.

Thank you for the info & pix!
 

Paolo B

Tinkerer
Nov 27, 2021
275
158
43
Switzerland
Honestly I don’t remember, most likely I recapped the PSU, though.
The unit I have stutters a bit when I power it up, but then it just works.
But I’ve got to admit I’m not using it since a while…
Another likely issue is the parking position bumper of the r/w head. They tend to become sticky, due to deterioration of the rubber. It’s a reasonably easy fix, but you need to open the HD enclosure, which is never recommended.