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pc clock sometimes incorrect

Posted: Thu Aug 04, 2005 9:07 pm
by Ogg
T30 (2366-83u). Sometimes, when I turn on the computer, I notice that the clock is almost always 2 hours behind from the actual time. The DATE is correct. I'll make the clock correction and cary on.. no problem. At next reboot next day, the clock MAY be fine. BUT, the following it day it might be 2 hours behind again. The battery is charged. I think the problem occurs when I don't have the laptop in the AC adapter when the computer is off. What needs to be fixed? I tested the battery on its own and learned the battery is good for nearly 2.5 hrs.

Posted: Thu Aug 04, 2005 9:16 pm
by GomJabbar
I believe it could be your CMOS battery, sometimes called the backup battery. It is may be a coin cell with some leads attached, but I am not familiar enough with the T30 series to say. You can find it by looking in the Hardware Maintenance Manual. Below is the link.

You can download the Hardware Maintenance Manual by starting at the following link. Make your choices in the first two drop down boxes, click on continue, then click on publications.

http://www-3.ibm.com/pc/support/site.ws ... date=false

Posted: Fri Aug 05, 2005 7:39 am
by jdhurst
Also check which timeserver your clock is connected to. The default internet timeserver for XP is time.windows.com (look in the clock in your system tray). If you are on a domain, the clock could get connected to a different time server that may not be correct. ... JD Hurst

Posted: Fri Aug 05, 2005 9:28 am
by Ground Loop
GomJabbar wrote:I believe it could be your CMOS battery, sometimes called the backup battery.
This may be the case, but I'd be surprised. Usually when the CMOS battery dies, the computer not only fails to keep time, but forgets it altogether. I haven't seen one that stops the clock, but remembers the last time -- frozen. Are ThinkPads unique this way?


Is the clock *exactly* two hours off? If so, then jdhurst is onto something -- your time source and your laptop probably have a timezone disagreement.

Also, if you boot Linux, make sure that the "hardware clock on GMT" option isn't being used.

Windows, infinite wisdom, likes to keep the CMOS clock on Local Time and adjust for GMT when communicating time, while Linux prefers to have GMT/UTC in the hardware clock and adjust it for your local timezone when dates are displayed.

Posted: Mon Aug 08, 2005 4:49 pm
by Ogg
Ground Loop wrote:
GomJabbar wrote:I believe it could be your CMOS battery, sometimes called the backup battery.
This may be the case, but I'd be surprised. Usually when the CMOS battery dies, the computer not only fails to keep time, but forgets it altogether. I haven't seen one that stops the clock, but remembers the last time -- frozen. Are ThinkPads unique this way?


Is the clock *exactly* two hours off? If so, then jdhurst is onto something -- your time source and your laptop probably have a timezone disagreement.
Hmmm... I think is was excatly 2 hours off. Now I can't check that. I was just looking it over and doing some anti-vir, defrag, etc.. work on it for a friend. I believe the quirk happend TWICE, and each time the clock was 2 hours behind. But how can a time server be an issue when the computer isn't even connected to the 'net before bootup completes?

Posted: Mon Aug 08, 2005 4:52 pm
by Ogg
jdhurst wrote:Also check which timeserver your clock is connected to. The default internet timeserver for XP is time.windows.com (look in the clock in your system tray). If you are on a domain, the clock could get connected to a different time server that may not be correct. ... JD Hurst

I didn't check that. But how can a time server be an issue when the computer isn't even connected to the 'net before bootup completes?

Posted: Mon Aug 08, 2005 5:14 pm
by leoblob
Ground Loop wrote:I haven't seen one that stops the clock, but remembers the last time -- frozen.
Actually, my 365X did exactly this, when the CMOS battery was dead. I can't imagine how/why this could possibly happen, but when I put in a new battery ("coin cell") the problem went away... ???

As for being exactly 2 hours off... I have no idea on that, either. I guess I would just replace the CMOS battery and hope for the best... ??

Posted: Mon Aug 08, 2005 5:27 pm
by jdhurst
Ogg wrote:
I didn't check that. But how can a time server be an issue when the computer isn't even connected to the 'net before bootup completes?
A timeserver checks what it is connected to (internet, domain, whatever) and doesn't check if it isn't connected. My two PC's are not domain-connected and use time.windows.com and are never off by more than a minute or two occasionally, and are correct most of the time.
... JD Hurst

Posted: Tue Aug 09, 2005 6:00 am
by egibbs
Also, if you are synching with a PDA, cell phone, etc. check the time zone settings on it.

Ed Gibbs