Thinkpads Forum

In the last day the hardware clock on my T61 has started gaining time. I booted up, after the computer being off over night, and the clock had gained 30 minutes. Then after the computer was shutdown for another 12 hours and rebooted it had gained 20 minutes.

Now I've been running the computer for about an hour and checking the hardware clock with hwclock (I'm running Arch Linux). In the last hour the hardware clock has gained 1 minute and 30 seconds, although the clock in my desktop panel reads the correct time.

Does this mean the CMOS battery is dying? Something else? The computer is only about a year and a half old. I've had much older laptops that have never had the CMOS battery die. And does it really make sense that the hardware clock would gain time (rather than lose time) when the battery dies?

Thanks for any help.

Possible causes - Sound driver or CMOS Battery -
http://forum.thinkpads.com/viewtopic.php?f=25&t=37794

Harryc wrote:Possible causes - Sound driver or CMOS Battery -
http://forum.thinkpads.com/viewtopic.php?f=25&t=37794

Yeah, I saw that post. It's two years old, about a different model computer (in fact not even a Thinkpad). So I don't have the same BIOS and it sounds like Lenovo addressed the problem with that ThinkCentre desktop a long time ago.

I also mentioned that I'm using Arch Linux, not Windows, rulling out the sound driver issue from that post on the software side.

That leaves the battery, unless it's an issue with Arch Linux. Would the harware clock really run consistently faster, when the battery is dying? Has anyone else experienced this?

It's starting to look like it is a problem with Linux, continually updating the hardware clock for some reason and setting it faster.

There's a thread on it here, if anyone using Linux is interested:

http://bbs.archlinux.org/viewtopic.php?id=85231

You can download a copy of PC Doctor for DOS for the T61 from here:

http://www-307.ibm.com/pc/support/site. ... 56222.html

as that diagnostic should have a Real Time Clock (RTC) test which can rule out the hardware as being the source of the problem. There should also be some sort of ntpd (Network Time Protocol daemon) that you can run which will go out and synchronize your system to an internet time server. I don't use Linux but I run a small Windows utility program (DS Clock) that basically does the same thing.

rkawakami wrote:You can download a copy of PC Doctor for DOS for the T61 from here:

http://www-307.ibm.com/pc/support/site. ... 56222.html

as that diagnostic should have a Real Time Clock (RTC) test which can rule out the hardware as being the source of the problem. There should also be some sort of ntpd (Network Time Protocol daemon) that you can run which will go out and synchronize your system to an internet time server. I don't use Linux but I run a small Windows utility program (DS Clock) that basically does the same thing.

Thanks! I'll try PC Doctor.

Yeah, I can use ntpd with Linux. But I'm not always connected, so it's not a great solution, since I was gaining over a minute an hour.

Right now deleting a certain file related to how Linux sets the hardware clock and letting the system regenerate it seems to have solved the problem. Either that, or it was leaving my thinkpad plugged-in overnight to recharge the CMOS battery, which was one of the solutions the ThinkPad Hardware Maintenance Manual suggested.

As far as I know, the CMOS battery is NOT rechargeable. Those batteries are standard lithium cells, not lithium-ion (which are rechargeable) and usually last about 5-7 years.