POST error 662 on IBM PS/1 - Model 2155

tonyk · May 15, 2023

I dug up my ma's old IBM to work on for a class I was taking, and I'm still trying to get it into complete working shape. Most everything on this computer is still functioning properly despite not having been touched for over 20 years, but the original floppy drive (a combo unit) had a lot of dark spots, likely mold, on the connector board. I swapped it out with a Teac FD-55GFR 7149-U5 unti my instructor had laying around, but I keep running into a 662 POST error whenever I start it up. I've tried a couple of different configuration settings in the BIOS, but keep running into this issue. I'm still fairly new to the world of vintage computer repair, so any advice would be greatly appreciated.

booboo · May 15, 2023

@tonyk the 662 error is literary "Wrong Diskette Drive Type". Did you set drive A to 1.2MB and Drive B to none?

tonyk · May 16, 2023

I have, but every time I restart the computer, it flips the configuration I set (sets drive A as not installed and drive B to 1.2MB instead of the other way around) and keeps throwing the error at me.

Caluser2000 · May 18, 2023

Show as a pic of how you have the fdd cable connected.

tonyk · May 18, 2023

Not sure how many photos I can attach (I'm on another forum that uses the same forum software, and it's limited to five media items), but here's what I was able to take pictures of.