Lisa Won't Boot. Advice? — #2

Post #2 by Nathan

Source Forum	68kMLA
Category	Hardware
Post Date	Fri, 21 May 2010 - 21:21
Original URL	https://68kmla.org/bb/threads/lisa-wont-boot-advice.20611/

Post

Possible read this PDF: http://www.mjposner.com/LISA.pdf (The Apple Lisa HandbooK). The fact that the floppy is clicking suggests that it expects to boot from a disk. Is there a difference between the clicks for disk access and those to eject? If you are comfortable opening the computer, you might hunt around for burn marks or bad solder joints with some kind of magnifying tool. Perhaps there is something wrong with the video circuit (unless that's some kind of diagnostic test pattern). Can you hook it up to a tv (if that isn't one) and if so does it make any difference? Possibly also check out this site: http://www.applerepairmanuals.com/lisa/ Especially this page: http://www.applerepairmanuals.com/lisa/lisatech/page10_11.html

Check out this quote from the bottom of that page (which is part of a whole section):

Automatic Startup Tests

Every time you turn on the Lisa, it runs an exhaustive series of tests in the following sequence:

ROM Checksum

If the ROM Checksum fails, the computer hangs. When the CRT warms up, the screen may appear blank or it may display random patterns. These symptoms indicate a problem with the ROM chips, which are on the CPU board at locations D13 and D14. There are several things to check before ordering new ROMs:

1. Make sure the chips are oriented correctly. The notches should be pointing up. There were several ROM versions. Someone could have tried to install new ROMs, put them in backwards, and given up at that point.

2. Make sure they're in the right sockets. If you have a stock Lisa with "H" ROMs, part number 341-0176-H should be in the socket at D14, part number 341-0175-H should be in the socket at D13. If you have a modified Lisa with "3A" ROMs, part