I purchased an Apple III which displays the attached screen rather than booting.
I tried the following to no avail:
- reseated all chips, including all memory chips
- cleaned up some rust and residue wherever I could see on chips (some was around floppy connection; worst looking was chip 341-0035-00 which, however, seems to be keyboard encoder, so probably not the culprit)
Any ideas how to proceed fixing this machine are welcome.