[comp.sys.ibm.pc.misc] Losing time-of-day from CMOS!

jaffe@iccgcc.decnet.ab.com (06/24/91)

When my PC, a 10-month old Gateway 386/sx, is shut off it loses the time of day
retained in the CMOS.  The BIOS catches this and forces entry to the setup
utility.  After the time is reset, the time updates OK.

I talked to a tech support rep at Gateway, but all he could suggest was to
replace the system board.  This seemed rather radical to me (since my 1-year
warranty is about to expire, and I don't relish starting over with new hardware
with such short-term support), so I elected to hold off a bit and continue to
explore the problem.

The hardware manual suggested that possibly the battery was low, and that
leaving the system on for 24 hours would recharge it and fix my problem.  It
didn't.

The rest of CMOS seems to be unperterbed, including the date, so I'm fairly
sure that it's not the battery.

Can anyone out in netland suggest what a possible cause for this problem might
be?

tmkk@uiuc.edu (K. Khan) (06/25/91)

In article <1991Jun23.121135.4951@iccgcc.decnet.ab.com> jaffe@iccgcc.decnet.ab.com writes:
>When my PC, a 10-month old Gateway 386/sx, is shut off it loses the time of day
>retained in the CMOS.  The BIOS catches this and forces entry to the setup
>utility.  After the time is reset, the time updates OK.
>
>The rest of CMOS seems to be unperterbed, including the date, so I'm fairly
>sure that it's not the battery.
>
>Can anyone out in netland suggest what a possible cause for this problem might
>be?

My CMOS/clock has the same problem. Since the chip is soldered onto the
motherboard, I haven't bothered to replace it (and which might account
for your tech's recommendation that you replace the motherboard - board
swapping is about all some repair places do these days). My workaround
was to update the system time and date across my $25 Network from
another machine nearby which is on 24 hours/day. It won't work for
everybody, but it saved me from having to do without my '386 for a
couple weeks while the motherboard goes back to the factory. :-(

mlord@bwdls58.bnr.ca (Mark Lord) (06/26/91)

In article <1991Jun23.121135.4951@iccgcc.decnet.ab.com> jaffe@iccgcc.decnet.ab.com writes:
<When my PC, a 10-month old Gateway 386/sx, is shut off it loses the time of day
<retained in the CMOS.  The BIOS catches this and forces entry to the setup
<utility.  After the time is reset, the time updates OK.

On many systems, a bad "power good" signal from the power supply can produce
these symptoms.  There are two solutions/ways-to-verify-this:

	a) swap power supplies with a known-good system, and see what happens
on each system if the problem moves with the supply, then replace it.  Otherwise
there is likely a problem with the system motherboard.
	b) some motherboards include a jumper to cause the real-time clock
to use an on-board "power good" signal instead of that from the supply. If your
system has such a jumper, try moving it to see if the problem goes away.

-- 
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hpa@casbah.acns.nwu.edu (H. Peter Anvin) (06/26/91)

|> In article <1991Jun23.121135.4951@iccgcc.decnet.ab.com> jaffe@iccgcc.decnet.ab.com writes:
|> <When my PC, a 10-month old Gateway 386/sx, is shut off it loses the time of day
|> <retained in the CMOS.  The BIOS catches this and forces entry to the setup
|> <utility.  After the time is reset, the time updates OK.

It should be noted, too, that these sympoms can actually mean that the battery is on the whim.  I had a chain on similar problems with my Hyundai 286c a while ago: I replaced the battery and it ran fine.  Never had my (Award) BIOS said that the battery was bad, only it gave me frequent check sum errors.

	/Peter

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