Hi James,
you might be right, I first thought of an electronic problem because the board stopped working while it was connected to the LISA, it started up fine and it suddenly stopped working.
I will try to make a diagnostic for the board again, the problem seems not to be related to either one of the socket-ed chips and I am happy the COP 421 is not damaged since I have tested with the one from the working board and I got same results. I will test this evening again everything and keep you posted.
Thank you!
Alex
joi, 10 ianuarie 2013, 08:22:39 UTC+2, James MacPhail a scris:
>The IO Board is dead again.--
>
>with the other IO Board, everything works fine.
I'd guess that something physically happened to the board, rather
than electronically.
Can you recall what you did to the I/O Board between the time that
the board worked and when it stopped working? That may provide a clue.
You recently found a couple of traces that needed repair, so check
that area, and you swapped out the RAM chip(s) on the I/O Board, so
check that area too. In other words, check the areas where you might
have disturbed something. Also look for a solder splash or damaged
trace.
Good luck!