Hi all you symbolics hackers,
I have an XL1201 LispM which I am afraid has given up the ghost. I
was wondering if anyone may be able to help me identify this failure
mode and possibly help me bring it back to life. I purchased this
machine a couple of years ago when Symbolics had a group of them for
sale. It has never been a strong runner as far a machines go, it has
always tended to lock up after about an hour of use. Unfortunately, I
did not realize this until the 90 day warranty had expired.
Finally, it started lock when powered up and I would have to gently
power cycle it a couple of times to get it to boot. Now I can't even
get it to do that much. This morning I tried to get it to go about 10
times, once it did manage to print some of the messages about loading
the FEP files, then it locked up. No other time was it possible to
get it to actually display anything.
The standard behavior is as follows.
Power up: The system "sounds" O.K. as it starts. You can here the
ESDI drive rattling like it normally used to.
The two voltage leds come on (+5 and +12 it think, I didn't
write that down.)
All the leds in the other group come on (fault, run, u0 ,u1).
The console brightens but no text appears.
Power up +1: Nothing.
Pressing the hardware reset button (the little one near the leds you
use a paper clip to press) results in one of four states.
1) No difference.
2) The leds change to fault + u0
3) The leds change to fault + u1
4) once the FEP actually started (not reproducible).
Currently, this machine has no external SCSI devices attached and has
no network connection. However, I do have a SCSI disc that was
attached to this machine which has LMFS on it. If the problem is that
the ESDI disk is dead I could probably get the system to run off the
SCSI disk if I had a clue about how to go about this.
Thank you for any help,
-Eric
It sounds like you have a shorted trace on some circuit board.
Generally after the machine/boards warm up and there is
cracked trace it will fail/lock-up as the heat expands the electronics.
You probably need a hardware tech to track the problem. They
generally use a cold spray of freon to cool components and
find the short.
Wade