Amiga 2000 Floppy Problem

[o***@gmail.com]

My Amiga 2000 has a wierd problem. Whenever heavily accessing a
floppy disk, the disk disappears and reappears. It's as though the
disk was removed. This happens with the internal DF0: and my external
drive as well. Something wrong with the diskchange signal, I would
think. Which chip controls the floppy drives? It's been so Iong
since I've worked on one of these, I can't remember.

[retroman]

Post by o***@gmail.com
My Amiga 2000 has a wierd problem. Whenever heavily accessing a
floppy disk, the disk disappears and reappears. It's as though the
disk was removed. This happens with the internal DF0: and my external
drive as well. Something wrong with the diskchange signal, I would
think. Which chip controls the floppy drives? It's been so Iong
since I've worked on one of these, I can't remember.

Could be a fault 8520 CIA,-very common problem.

[Clocky]

Post by o***@gmail.com
My Amiga 2000 has a wierd problem. Whenever heavily accessing a
floppy disk, the disk disappears and reappears. It's as though the
disk was removed. This happens with the internal DF0: and my external
drive as well. Something wrong with the diskchange signal, I would
think. Which chip controls the floppy drives? It's been so Iong
since I've worked on one of these, I can't remember.

U300 8520. Try reseating it, and if that fails try swapping it with U301
8520 and see if that fixes the floppy problem (and likely introduces a
serial device problem).

[Thomas Richter]

Post by o***@gmail.com
My Amiga 2000 has a wierd problem. Whenever heavily accessing a
floppy disk, the disk disappears and reappears. It's as though the
disk was removed. This happens with the internal DF0: and my external
drive as well. Something wrong with the diskchange signal, I would
think. Which chip controls the floppy drives? It's been so Iong
since I've worked on one of these, I can't remember.

Before you play with the chips in the system, make sure that the drive
disk detect sensors are clean and operating properly. They are usually
in front of the drive, a tiny switch or an optical sensor that detects
whether a disk got inserted. Try to get rid of the dust (with a q-tip
and a bit of alcohol) first before trying any other experiment.

Greetings,
Thomas

[fabril]

Post by Thomas Richter
Before you play with the chips in the system, make sure that the drive
disk detect sensors are clean and operating properly. They are usually
in front of the drive, a tiny switch or an optical sensor that detects
whether a disk got inserted. Try to get rid of the dust (with a q-tip
and a bit of alcohol) first before trying any other experiment.
Greetings,
        Thomas

I had the same problem on at least 2 Chinon drives. I had to desolder
the microswitch and replace it on both of them. I tried to open one to
clean the contacts, but it's not easy: there are two terribly small
and delicate springs in there!

[Amiduffer]

Post by fabril

Post by Thomas Richter
Before you play with the chips in the system, make sure that the drive
disk detect sensors are clean and operating properly. They are usually
in front of the drive, a tiny switch or an optical sensor that detects
whether a disk got inserted. Try to get rid of the dust (with a q-tip
and a bit of alcohol) first before trying any other experiment.
Greetings,
Thomas

I had the same problem on at least 2 Chinon drives. I had to desolder
the microswitch and replace it on both of them. I tried to open one to
clean the contacts, but it's not easy: there are two terribly small
and delicate springs in there!

Hell. That's happening to the DF0: floppy in my A3000. Sigh, time to
take it apart again. Thanks for the info. What a puzzle this has been.