MFM drives

as I was going through my parts today, i decided to test some 5 old mfm controller cards I was given by someone at work. it turns out that 5 mfm hard drives i have have gone "bad" again (they worked previously), and all 5 controller cards have failed. it seems the only drive combination i have that works is a kalok drive, and a full size adaptec controller card that came in the 286 im testing all these in. over the past year, i betcha i've bought and thrown away almost 40 bad controller cards! the drives i know worked before, so i can just call debug and low level them again. ive already tried cabling combinations, jumper and bios settings, swapping known good parts out, and so forth. has anyone else had a fantastic failure rate with mfm controller cards? seems like i have better luck with reviving hard drives. incidentally, would anyone know what the proper jumper settings would be for an 8bit mfm controller card? one is a WD1002-27X and the other is a WD1002A-WX1. they are similar in appearance, but minor changes in chip layout and jumper settings. both these cards won't init a good hard drive. david