On Mon, Sep 7, 2020 at 12:57 PM Antonio Carlini via cctalk < cctalk at classiccmp.org> wrote: Antonio, If there is no stiction then tapping the disk or opening to spin the disk manually does nothing useful IMHO other than expose the surface to dust. It could be that you need a new controller, you could always try a transplant of the controller electronics from one drive to another to dump the data. Has to be the same type of drive, etc. It's all a percentages thing, you might save one out of 4 swapping around electronics. If you have nothing to lose and you don't mind possibly making it worse ... Bill

Antonio Carlini wrote: I have some RZ28 (2GB?) disks but I don't recall having any difficulties with them. I do have some RZ29B (4.3GB) disks that fail to spin up when requested to unless they are given some physical encouragement in the form of a sharp twist or some vigourous tapping. They can be heard to make a very faint and short purr when trying and failing to spin up but no clicking noises and no data issues. I have more than one RZ26L (1.05GB) disk which I reinitialised and installed a new system on which then failed horribly with nasty clicking noises after working nicely for a very short time. I haven't found any way to fix this condition and I don't know if almost completely rewriting them is what triggered it to happen or maybe it was because of sudden activity after years of idleness. I didn't try freezing them. I also have one Compaq 9GB SCA disk which made heart-stoppingly loud clunks and clicks at irregular intervals but continued to function normally in this condition for several years. I had copied it's contents to a new disk but left it in place to see how it would fail. It didn't. I eventually took it out and examined it, found nothing obvious wrong, put it back in and decided to make an audio recording of the noises it had been making. Of course, it then refused to make any more noises after being disturbed and continues to work normally without any data issues whatsoever. Regards, Peter Coghlan.