Compaq Portable III Floppy Drive

I picked up a Compaq Portable III in a salvage lot. I had no problems with the machine until the 5 1/4" 1.2mb floppy apparently failed. If you attempt to read a disk, the disk is rendered entirely unusable, in fact you can not even reformat it in another machine. Knowing that it was unlikely that I would find another 5 1/4 drive, I decided to replace it with a 3 1/2" 1.44mb drive. I had to modify a pair of mounting rails to get the drive mounted correctly and fashion a piece of plastic to fill in the empty space around the drive, and it ended up looking pretty good physically. I booted the machine, it reported the difference in the drive, I ran the setup program and that all went well. Then it came time to read a disk the machine would not access the drive. When I grabbed a spare drive I happen to grab a Sony MFD-17W-50L. Believing that I might have grabbed a bad drive, I tried several other drives. I tried another Sony MFD-17W-50L, a Sony MFD-17W-5GD, a Newtronics/Mitsumi D359T3, and a TEAC FD-235HF. The results were that none of the Sony drives would work and the others worked fine. I checked the 5 1/4 drive and it was set for an ID of drive 1 as expected since there was the usual twist in part of the ribbon cable. The drives that worked were set to an ID of 1. One of the Sony's was set to an ID of 0, but I tried all ID's on the Sony's to no avail. I finally installed the TEAC drive and everythng is fine. I am curious as to why the Sony's would not work. Anybody got any insights, or had problems with Sony drives in other machines. TIA Mike Thompson