[comp.sys.mac.hardware] Mac HALTING

piper@s5000.rsvl.unisys.com (Piper Keairnes) (04/29/91)

I'm having some rather serious problems with my Mac IIci. During normal
operation, the Mac will HALT. No error, no screen garbage, nada. All I
get is an otherwise normal looking screen on a computer that isn't
operating. When I try to reboot, the screen doesn't even make it to the
stage where the corners of the screen are "snipped". It just hangs
indefinitely.

At other times, the Mac will go through the entire boot process, but the
mouse and keyboard will be inoperational. What's curious is that the mouse
won't move and the keyboard doesn't respond, but the Finder continues its
startup process. I had thought that there was a RAM problem, so I bought
new RAM and replaced the old with the new. Same problem. There was a period
of a week where the problem went away though. Like I said... curious.

A local technician quoted me $60/hour to look for the problem with no
guarantees. I'd like to forego the expense if possible. He gave me a few
suggestions over the phone, but I had already tried them all, so I don't
credit his ingenuity and technical know-how.

Has anyone experienced similar problems? Anyone have a suggestion/solution?

Things I "know" or have tried:
  1) Software is not the problem, as far as I can tell. Doing a cold boot
also hangs occasionally before the Happy Mac appears and before the screen
edges are clipped. I've disconnected ALL devices and tried to boot off of
floppy (origial 6.0.7) with the same results. By all devices I mean: the
only thing attached to the IIci box was a power cord, and I took out the
internal disk drive (Quantum 105 Pro, SilverLining driver).
  2) The RAM seems to be fine. I've switched SIMMs in and out in a number
of permutations of old and new, this bank and that bank, etc. Is it
possible that the SIMM slots themselves are foo-bar? Dirty, scummy?
  3) I have a roommate who wants to drop the IIci box an inch or so to
settle any chips that might be loose. I'm, to say the least, a little
leary of doing this. Maybe a last resort.
  4) The computer is actually a IIcx box with a IIci motherboard upgrade.
I bought it from Shreve systems. Warranty is now expired.

Grunt, sigh!

-- 
    Piper Keairnes     *     piper@rsvl.unisys.com      *  Purdue  University
  Unisys Corporation   *  uunet!rsvl.unisys.com!piper   *   Computing Center
Open Software Products *     ar4@sage.cc.purdue.edu     *      Consultant

piper@s5000.rsvl.unisys.com (Piper Keairnes) (04/30/91)

<173@s5000.rsvl.unisys.com> piper@s5000.rsvl.unisys.com (Piper Keairnes) writes:

>I'm having some rather serious problems with my Mac IIci. During normal
>operation, the Mac will HALT.

Follow-up:
  During a startup last night, I happened to press the space bar on the
keyboard and watched the mouse jump across the screen. Successive
key-presses made the mouse jump all over the screen. Any chance my ADB
connections are hosed? I've currently moved my mouse to the second ADB
connector on the keyboard.
  I had heard a while back that removing ADB connections while the
computer is operating is a no-no. I don't recall having done this
recently, or at all for that matter, but I have roommates who do use my
computer and I can't watch all the time. Would disconnecting the mouse or
keyboard while the IIci is operating cause the long term problems I've been
having. If so, what's the cure? How much $$ are we talking?

Good grief, this is getting annoying. :-)

-- 
    Piper Keairnes     *     piper@rsvl.unisys.com      *  Purdue  University
  Unisys Corporation   *  uunet!rsvl.unisys.com!piper   *   Computing Center
Open Software Products *     ar4@sage.cc.purdue.edu     *      Consultant