PC164-repair

[axp amazing ch]

Hi

I have a PC164/500 which is driving me nuts.
I think, it has a bad contact somewhere, but
I don't find it.

So far, I changed every changeable part beside
the CPU and the Mainboard (RAM, Gfx-\SCSI-\
Networkcard, Power Supply, Floppy, Harddisks).

Now I'd like to know, if there's any place,
which would fix my board or replace it (I
woud't mind to get a used board)?

Originally, the Computer is from Vobis
(Switzerland), but they have troubles
repairing it (somewhat about they got it
from Vobis Germany, but they do not
support it anymore and Vobis Switzerland
has no contracts with Compaq, so Compaq
doesn't repair it either...).


Alternatively, I'm interested in new Ideas
to diagnose the problem.

Symptoms:
-Machine locks up after random times (between
1h up to 2 Month).

-If it hangs, then only HW-Reset brings it to
life again, but it'll crash again (mostly during
fsck-ing 45GB of Diskspace :(

-Switching off and on doesn't help.

-I used to think it's the power-connector
to the mainboard, because when I wiggle on this
one, I can mostly get the machine working again.
But I resoldered the connector and I changed the
PS without any results, so it's probably not
the problem.

-Also when I changed the RAM, it worked for a while,
but then it crashed again. I then reinserted the old
RAM (now there are 8x32MB in there) and the machine
worked for another month or so.

I think, everything I do in there moves something,
which allows the machine to run again for a while
until that something fails to work (maybe because
of vibration from the ventilators or due to thermal-
expansion).


There are 3 different crashes i remember:

1. A 2-line message scrolls indefinately over the
screen:
"CIA machine check: reason for machine check unknown
vector==0x660 la_ptr=0xffffffc0000..."
(not shure about the numbers. it scrolls really fast)

2. Just a black Screen. Everything dead (no answer
to network, no reaction to ctrl-alt-del or any
other keypresses beside reset)

3. Scrolling numbers on screen counting up (haven't
seen this one in a while, so I don't remember how
it looks like).


The machine:

PC164, 21164, 500MHz
8x32MB RAM
Matrox Millenium 4MB
Networkcard with DE4xx
NCR-SCSI 53C8xx
3.5" Floppy
5x9GB-HD in external case
3 Ventilators (1 in PS, 1 in front of case, 1 on CPU)

I don't think Software matters, because it somethimes
hangs in ARC-Console even before milo gets loaded...

Bye
 dworz

PS: I'm a microtechnics-engineer, so I know how to
use a soldering iron or a Osziloscope (but I won't
randomly resolder smd-chips or start hw-debugging
without schematics...)


--
Want to flirt? -> http://www.amazing.ch/
Your CPU is bored -> http://rc5.amazing.ch/rc5/