folks,

don't give up on your old mac's just because it can't detect the hard drive when you try to boot/install

I started out trying system 7.5.3 and at first it didn't detect the hard drive at all... not even the disk utilities disk would help...

but then I tried just about every version
and system 7.5 (7.5.0 ) worked perfectly

I had to first use drive setup on the the disk utilities disk to re-initialize the hard drive
I also had to use Update in the same program to format it to the correct format.. (the first option)

I also had to try installing system 7.5 about 13 times before it didn't crash mid install so don't give up if that happens either... just re-write the floppy disk that it failed on from another computer and try again..

Anyways, it's not just trying the right version that got it to work.. it was continuously firing it up everyday that got the drive to load. I guess sometimes they just need to spin long enough to kick the dust off of them.

so to reiterate, your steps are to:
.try every version of disk utilities - when one works... open "drive setup", initialize, update (mac format)
.try every single version of system 7- if the installation fails.. keep trying/re-writing the disks
(google: powerbook 180c specs... so you can see the compatible versions)
.continue to start the machine up and shut it down at least once a day

eventually, if you're lucky it should work for you too

figured I'd share so we can restore more of these vintage machines before they are lost forever