|Look in the bios Setup and see if you can select a 5 1/4 floppy drive. Some newer bioses no longer have that. |
If it doesn't have that, you can't connect a 5 1/4 drive.
If it does have that, it must be set to a 1.2mb one, not a 360kb one.
(Some bioses auto detect the floppy drive type and there is nowhere in the bios you can select the type - in that case, you won't know whether the bios can detect a 5 1/4 drive until one is connected properly.)
You need a floppy data cable that has one or two of the older type of floppy connector (two on a three connector data cable) - a larger one that has a divider in it that lines up with the space in the contact strip on the drive's data connection - the mboard end connector has the same smaller connector as the newer type floppy data cables have -
some have both the older and newer type of connectors for the drives -
StarTech FDAT 32-Inch Universal Floppy Drive Cable
or - you need a regular newer type floppy cable, and an adapter (relatively rare) you plug into the contact strip on the drive that you can plug into the newer data cable. If you don't have any such thing, if there is a local place that sells parts for older computers, try looking there, or if you know someone who has parts for old computers, ask them, or buy it off the web.
If the 5 1/4 drive is connected by itself, the drive connects to the last connector connection on a 3 connector floppy cable, or in any case, the one after some of the wires in that cable are flipped over.
NOTE that really old MFM or RLL (pre IDE) hard drives use the same older type of 34 wire larger data cable connectors on their data cables, but different wires in the cable are flipped over, and that data cable won't work with 5 1/4 floppy drives. Most of those have two connectors on the data cable, rather than three.