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CMOS Problem
Miscellaneous PC Hardware Miscellaneous PC hardware topics (comp.sys.ibm.pc.hardware.misc)
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CMOS Problem -
04-10-2007
, 04:44 PM
#2
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I have an ABIT KD7A processor, and CMOS does not seem to hold its charge very well. Each time I reboot, I need to reset dates, etc. I discovered this problem when my machine would not come up in any way. PSU, CPU, and MB all seemed dead. I discovered that the 3v batter was reading 2.8v, so replaced it. Actually, just taking it out of the computer brought it to life. After awhile, I put in the new battery. It seems like it took repeated uses to get cmos charged up. It worked fine for a few days, but now, with the battery still in, it has gone back to losing cmos each time I boot. The battery is not hot. Suggestions? |
draining it. That coukld well be an additional buffer capacitor
(elecrolyte), since they develop leaks after some years. The way to
really diagnose this is to measure how much current is taken from
the battery. If it is a capacitor wioth low isolation resistance,
then it has to be removed or replaced as final fix.
Arno
#3
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Previously W. Watson <wolf_tracks (AT) invalid (DOT) com> wrote: I have an ABIT KD7A processor, and CMOS does not seem to hold its charge very well. Each time I reboot, I need to reset dates, etc. I discovered this problem when my machine would not come up in any way. PSU, CPU, and MB all seemed dead. I discovered that the 3v batter was reading 2.8v, so replaced it. Actually, just taking it out of the computer brought it to life. After awhile, I put in the new battery. It seems like it took repeated uses to get cmos charged up. It worked fine for a few days, but now, with the battery still in, it has gone back to losing cmos each time I boot. The battery is not hot. Suggestions? Hwat it the current battery voltage? If it is <3V, the something is draining it. That coukld well be an additional buffer capacitor (elecrolyte), since they develop leaks after some years. The way to really diagnose this is to measure how much current is taken from the battery. If it is a capacitor wioth low isolation resistance, then it has to be removed or replaced as final fix. Arno |
Wayne Watson (Nevada City, CA)
Web Page: <speckledwithStars.net>
#4
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I replaced it with a new battery shortly after discovering the problem and it didn't help. The voltage remained above +3, and probably still is. I was unexpectedly called out of town for 6 days and just got back. |
Arno
Quote:
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Arno Wagner wrote: Previously W. Watson <wolf_tracks (AT) invalid (DOT) com> wrote: I have an ABIT KD7A processor, and CMOS does not seem to hold its charge very well. Each time I reboot, I need to reset dates, etc. I discovered this problem when my machine would not come up in any way. PSU, CPU, and MB all seemed dead. I discovered that the 3v batter was reading 2.8v, so replaced it. Actually, just taking it out of the computer brought it to life. After awhile, I put in the new battery. It seems like it took repeated uses to get cmos charged up. It worked fine for a few days, but now, with the battery still in, it has gone back to losing cmos each time I boot. The battery is not hot. Suggestions? Hwat it the current battery voltage? If it is <3V, the something is draining it. That coukld well be an additional buffer capacitor (elecrolyte), since they develop leaks after some years. The way to really diagnose this is to measure how much current is taken from the battery. If it is a capacitor wioth low isolation resistance, then it has to be removed or replaced as final fix. Arno -- Wayne Watson (Nevada City, CA) Web Page: <speckledwithStars.net |
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