The usual are:
1. Try diskettes that work elsewhere.
2. The BIOS is set to 1.44M A:
3. The floppy cable and power cable is snugly in place.
4. A new floppy cable.
5. A new floppy drive.
6. Another motherboard.
Your post is void of your attempts. And no mention if the drive lights up.
the A drive is not working when you put a floppy in it says cabt read the specified device ive tried lots but it says the same thing why does it keep saying that