14 Apr
2005
14 Apr
'05
7:16 p.m.
Warning : I've never actually seen an AIM65 'in the flesh'...
My AIM 65 has been sitting in the original box since about 1985. I
think it was working when I packed it up, the only reason I packed it
up was I got my first Mac and didn't have room on my desk for both, so
the AIM got packed.
Anyway, I got out my power supply, checked it out, sure enough +5v was
still +5v and +24 v was still +24v. I then unpacked the AIM, trying to
be as "static sensitive" as possible, then visually inspected it for
obvious problems (anti-static material stuck on pins) and then did a
little re-seat of all the socketed ICs. plugged in the keybaord,
connected the +5v only and applied power... Nothing, no display,
Doesn't the AIM use a vacuum fluorescent display? Does it get it's power
from a DC-DC converter on the board, or from the 24V
input? If the
latter, you'll get no display without the 24V supply. If the
former, you
could check the output of the DC-DC converter with your voltmeter.
[...]
Well, remove power, inspect the board again, blow
off any dust,
gently, partly remove all the socketed ICs (not out of the sockets) in
hopes that maybe if there was some oxidation it would wipe it off.
Connected the +5v only and turned it on again... nothing, nada, zilch
(bummer)
I don't have a scope or anything, I only have a VOM, so my testing is
rather limited, I don't even know anyone who still has an o'scope.
Any ideas of what I could try?
Well, a logic probe would be _very_ useful. You would at least be able to
see if the clock was running, ff bus lines were doing anything, etc.
But I guess you don't have one....
Is your VOM analogue or digital? If it's analogue, you could measure the
voltage on the address and data lines. If you get a voltage 'in the
middle', it's likely that line is changing -- it's certainly not stuck
high or low. All the data lines and at least the lower order address
lines should be chnaging state.
-tony