@pernia @dcc @pwm If one of them boots and the other one doesn't, why even bother with it? If the laptop is rotting and falling apart, why fiddle with it instead of just doing the thing that works? You don't like the disk, boot it from a USB stick or PXE-boot it. Like, set up a tftp and filesystem server on your desktop machine, boot the thing over ethernet. No disks involved. That is what I am doing with my completely busted T500. (Screen broke off because of the problem with the hinges on the T500, battery was already long-dead, then the disk died.)

Or just go to the ewaste recycling thing with $10, buy whatever looks closest to working, take it home, try to make it work, and if it doesn't, get another $10 and repeat the process until you have enough working parts.