I have a powerbook 145 that I am trying to repair with a parts 140 I have. Everything works except the floppy. I tried both that I have and got the same result, nothing. It doesn't do anything at all if you put any disk in it. no head movement, no spinning, the computer doesn't seem to notice at all. I also tired a second main board, Unfortunately the donor 140 had a serious battery leak and damaged the processor daughterboard, so thats the only part I cant swap test. I thought the SIWM chip on the main board handled everything for the floppy, so I figured swapping the mainboard would be enough to rule out a controller issue. I did verify that there was power at the drive. Does anyone have suggestions? Or some explanation of how the SIWM chip works so I can hook up my logic analyzer, I haven't been able to find much online.
