[comp.sys.ibm.pc] HELP! Compaq Reboots while on UPS!

cjl@ecsvax.UUCP (Charles Lord) (08/24/87)

I have a curious problem that I wonder if anyone else has seen.
I have an otherwise functioning Compaq Deskpro that will reboot
sporatically (sp?) every few hours on its own if left on a 
Tripp-Lite UPS.  It has done it so far with two separate UPS units
that work great with IBM, Zenith, No-Name Taiwan, Wells-American,
and other computers in the building, but the Deskpro will not run
without rebooting every few hours while plugged into the UPS.

Mind you, the power did not go off during that time as the UPS
alarm never sounded!

The computer runs 8-12 hours a day with no problem if plugged
directly into the wall (as long as the utilities co-operate),
but is unreliable when just plugged into the UPS.  Go figure..

Note to those unfamiliar with the Tripp-Lite: It is NOT a 
problem with the converted voltage/waveform/etc as the UPS
normally passes the line AC to the device and cuts over to
its square wave output on power failure.  That is not the problem.

Thanks for any feedback!

Charles Lord
cjl@ecsvax.UUCP     ...!decvax!mcnc!ecsvax!cjl

gof@crash.CTS.COM (Jerry Fountain) (08/25/87)

In article <3744@ecsvax.UUCP> cjl@ecsvax.UUCP (Charles Lord) writes:
>I have a curious problem that I wonder if anyone else has seen.
>I have an otherwise functioning Compaq Deskpro that will reboot
>sporatically (sp?) every few hours on its own if left on a 
>Tripp-Lite UPS.  It has done it so far with two separate UPS units
>that work great with IBM, Zenith, No-Name Taiwan, Wells-American,
>and other computers in the building, but the Deskpro will not run
>without rebooting every few hours while plugged into the UPS.
>
>Mind you, the power did not go off during that time as the UPS
>alarm never sounded!

One test I would recommend.  Pull the plug on the unit while it is
running.  If the compaq reboots (perhaps 1 out of three pulls) your UPS
response time is not good enough.  Many early IBM-XT's had a problem with
UPS's because the UPS would pull up the line *just* after the the machine
had reset.  The solution is to replace a capacitor on the power supply
with one of a larger value.

Also a recommendation for anyone using a UPS.  Pull the plug on it at least
once a month any deep cycle the gel-cell.  Otherwise they tend to die (and
of course at the wrong time :-).  By deep cycling them you will lengthen
their lives a bit (and assure yourself that they are still functional).




-- 
-----Jerry Fountain-----
UUCP: {hplabs!hp-sdd,sdcsvax,nosc}!crash!pnet01!gof   ARPA: crash!gof@nosc.mil
MAIL: 523 Glen Oaks Dr., Alpine, Calif. 92001         INET: gof@pnet01.CTS.COM

jay@splut.UUCP (Jay Maynard) (08/26/87)

In article <3744@ecsvax.UUCP>, cjl@ecsvax.UUCP (Charles Lord) writes:
> I have a curious problem that I wonder if anyone else has seen.
> I have an otherwise functioning Compaq Deskpro that will reboot
> sporatically (sp?) every few hours on its own if left on a 
> Tripp-Lite UPS.  It has done it so far with two separate UPS units
> that work great with IBM, Zenith, No-Name Taiwan, Wells-American,
> and other computers in the building, but the Deskpro will not run
> without rebooting every few hours while plugged into the UPS.

There was a service bulletin Compaq put out on this very problem. It seems
that the original Deskpro power supply had a fuse in series with the
regulated 5 volt power supply line. The fuse clips they got from their
supplier were of poor quality in one particular batch.

Your dealer will be able to replace this power supply at no cost under a
Compaq extended warranty - IF you hurry. The program is referenced in
service bulletin #37 or 38 (have him call the dealer hotline if he's not
sure about this).

Act fast, though...the deadline is at the end of this month, according to my
source (an engineer in the compatibility testing group).
-- 
Jay Maynard, K5ZC...>splut!< | uucp: hoptoad!academ!uhnix1!nuchat!splut!jay
"Don't ask ME about Unix...  | (or sun!housun!nuchat)       CI$: 71036,1603
I speak SNA!"                | internet: beats me         GEnie: JAYMAYNARD
The opinions herein are shared by neither of my cats, much less anyone else.