[comp.sys.ibm.pc.misc] AT clone spontaneously reboots

waldman2@husc4.HARVARD.EDU (Bruce Waldman) (09/19/90)

A problem recently developed in my 4-yr old AT clone, after I added
a second 40mb hard disk.  (I am not sure if this is related, however).
The machine spontaneously reboots while running a program, or even
if just left idling.  This happened to me twice when I was trying to
load a new software package yesterday, although as I said, it even
occurs if I leave the machine running idle, or as a dumb terminal.
 
Any suggestions?

Bruce Waldman, bw@harvarda.bitnet
               waldman2@husc4.harvard.edu

frank@adiron.UUCP (Corradino) (09/22/90)

waldman2@husc4.HARVARD.EDU (Bruce Waldman) writes:
> The machine spontaneously reboots while running a program, or even

At the risk of sounding like I know what I'm talking about, you should
try swapping the power supply with a new one. When I tell them about the
symptoms, the hardware gurus around here smile knowingly, mention the word
"crowbar," and hand me a power supply catalog.  I think it means that the
output is momentarily dipping below 5 Vdc sufficiently to cause a reboot.
It's difficult to detect with a simple multimeter.

Frank Corradino                     email: uunet!adiron!frank
PAR Technology Corp.                phone: (315) 738-0600 Ext 338
New Hartford, NY  13413        disclaimer: you bet!

dave@westmark.WESTMARK.COM (Dave Levenson) (09/22/90)

In article <4209@husc6.harvard.edu>, waldman2@husc4.HARVARD.EDU (Bruce Waldman) writes:
> A problem recently developed in my 4-yr old AT clone, after I added
> a second 40mb hard disk.  (I am not sure if this is related, however).
> The machine spontaneously reboots while running a program, or even
> if just left idling.  This happened to me twice when I was trying to
> load a new software package yesterday, although as I said, it even
> occurs if I leave the machine running idle, or as a dumb terminal.

This is most-likely caused by the second hard disk overloading your
power supply.  The supply generates a power-good signal to the
motherboard.  If the supply is operated at its capacity or beyond,
this signal may occasionally drop, which normally forces a hard
reset and a cold boot of the PC.

You can probably replace your power supply for about $50.  Get one
rated at least 150 Watts, if you're running two hard disks.  If
you've got most of your expansion slots filled, or if you're using
other hungry peripherals, consider a 200-watt supply -- probably
priced about $75.

-- 
Dave Levenson			Voice: 908 647 0900  Fax: 908 647 6857
Westmark, Inc.			UUCP: {uunet | rutgers | att}!westmark!dave
Warren, NJ, USA			Internet: dave@westmark.com
[The Man in the Mooney]		AT&T Mail: !westmark!dave