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| Troubleshooting Floppy Disk Drives | Booting
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There is an apparent failure of the floppy disk drive
Explanation: There is a general failure of the floppy disk drive. This generally
means either an error message appeared at boot time saying that the floppy drive failed,
or other symptoms and analysis has led you to believe that the floppy drive may have
failed. Failure usually means that the disk is not accessible or usable at all and does
not respond to any attempts to use it. If the floppy drive is usable after booting the
hard disk but just will not boot, look here.
Diagnosis: There are many different causes of apparent floppy drive failures.
Floppy drives are very simple affairs and outright failure is quite rare--even in old
drives. Most of the time it is simply a matter of incorrect installation or configuration.
- First of all, if you have just installed this drive or have done any other work within
the PC box, check this troubleshooting list of common problems.
- Check to make sure that drive has power. Check the power connection to the drive. If
possible, try a different power connector.
- Make sure that the cable running to the floppy drive is connected properly and is not
loose or crimped.
- If you are just installing this floppy drive, make sure you don't have the cable
connected backwards. It is easy with many 3.5" drives to connect the drive backwards
because the cable is keyed but the connectors aren't always. Also, don't assume where pin
1 is on the drive, since this tends to vary with different hardware. If the drive's
activity light comes on as soon as the PC is booted and stays on, solid the whole time the
PC is on, this is a dead ringer for a floppy cable that has been connected backwards to
- If you are using two floppy drives then you should try to debug them one at a time,
otherwise they may conflict with each other and make debugging more difficult. If two
drives work separately but not together on the same cable, this usually means you are
either using the wrong kind of floppy cable
(make sure it has a twist in it) or one of the drives has had its jumpers changed from the
- If your floppy cable has five connectors, remember that these are in two pairs of two
connectors (each pair being a pin header connector and a card-edge connector, to allow you
to connect to either type of drive), one on each side of the twist in the cable. You
cannot use both connectors on the same side of the twist in the cable. The A: drive is the
one after the twist.
- Make sure that the floppy disk
controller is enabled in the BIOS setup.
- Check the BIOS setup and
make sure that the correct drive types are selected for the A: and B: drives. Choosing the
wrong type of drives can cause a failure to be reported.
- If you have a 5.25" drive that is not working, check the drive for physical
interference. These drives are large and I have seen problems like cables hanging down
into the mechanics of the drive and impeding its operation.
- If you cannot get the drive to work, the best way to check it is to swap it with a
similar drive in another PC. If your drive works in the other PC but its doesn't work in
yours, then you likely have a configuration problem. If the opposite happens then your
drive is either bad or misjumpered. It is often easier and cheaper just to get a new
- You may have a problem with the floppy disk controller. Try troubleshooting it here.
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