Hi guys,

Each time I reboot the tray clock shows a different time. I correct the problem but as soon as I reboot it has a different time again. I thought maybe I had a virus so I scanned with latest updated Spyware Doctor with anti virus, and no probs except for a couple tracking cookies that I deleted.

OS: Win XP SP3

Any help appreciated:S

Hi guys,

Each time I reboot the tray clock shows a different time. I correct the problem but as soon as I reboot it has a different time again. I thought maybe I had a virus so I scanned with latest updated Spyware Doctor with anti virus, and no probs except for a couple tracking cookies that I deleted.

OS: Win XP SP3

Any help appreciated:S

Reboot and during POST press Del to enter the BIOS see http://www.computerhope.com/issues/ch000192.htm

Go into CMOS settings and see if the date/time is different if so then you motherboard battery might need replacing.

See this article http://www.computerhope.com/issues/ch000554.htm

hth,
Darren

If it keeps on resetting then it means your bios battery is flat and needs replacing. Provided you have a standard pc and not a laptop, it will probably be a CR2032. They are available in quite a few shops and are quite cheap.

Thanks Darren for the reply.

In the CMOS the time was correct, but I still think you are on the money because the machine probably gave the battery a small charge while it was on earlier...the test will come when I boot it tomorrow.

Will post the result then.

Cheers 4 now

The battery is not a rechargeable one.

if its a dead battery then the date and year will revert back to when the bios was written.if not unplugged, it will keep time date until you unplug computer from power source !if it just time then you have another problem

Ahh, so the battery not rechargeable...well thats strange why it kept the right time after a reboot, but not after leaving it off for a day or two. Anyways...its back to its old tricks again after leaving it off for a day, so I went back into the bios and corrected it again and will see what happens tomorrow. It did keep the time though after 2 cold boots.

if its a dead battery then the date and year will revert back to when the bios was written.if not unplugged, it will keep time date until you unplug computer from power source !if it just time then you have another problem

Right caperjack, but I dont think that is the case here as it is usually a random time it comes up with each day, and not the same one which would have to be the case if it revert to manufacture date. And BTW, it never gets 'unplugged', but I do turn off the swich at the power point...this is the same yes?

Maybe you have Internet Time syncronised with Internet Time Server. If you have time zone setted to another zone, your clock will change to this different time zone after reboot.

Even if your pc is un-plugged your board still holds a small amount of charge. You can try this by pressing the power button (while un-plugged) and you will hear the fans spin for a moment.

I've read about this "Internet Time syncronised with Internet Time Server" buy I couldn't find it so I didn't bother to mention it.

What date does windows think it is?

Just click on corner on your clock and verify Zone time and Internet Time.

Even if your pc is un-plugged your board still holds a small amount of charge. You can try this by pressing the power button (while un-plugged) and you will hear the fans spin for a moment.
I

no a correct statement ,the power supply hold the bit of power you are referring to and not the mother board ,and its not enough to power the cmos chip that holds' the bios memory/settings ,and doesn't last ,unplug it and try pushing the power button in a couple of hrs time !

bottom line is this ,if its just the time changing and not the date too then it not a dead bios battery !check you time zone setting as suggested above

Right caperjack, but I dont think that is the case here as it is usually a random time it comes up with each day, and not the same one which would have to be the case if it revert to manufacture date. And BTW, it never gets 'unplugged', but I do turn off the swich at the power point...this is the same yes?

turning off the switch on the back of the tower is the same as unplugging it .
i have one simple question ,when it changes the time does it also change the date and year !

Just click on corner on your clock and verify Zone time and Internet Time.

Yep, the zone and internet time is correct

bottom line is this ,if its just the time changing and not the date too then it not a dead bios battery !check you time zone setting as suggested above

At the moment I think its both date and time changing, but cant be sure till I cold boot it tomorrow again, as I said b4...it keeps the right time when its warm so to speak.

I did synchronize with the internet this time.

CYA in 12 hours. Oh BTW...where do I find the battery?

Pressing the power button to to release power is a myth. The motherboard doesn't have any capacitors big enough to store power for more than a few milliseconds. The PSU has capacitors than are much bigger but even they can only store for less than half a second.

.it keeps the right time when its warm so to speak.?

as long as the computer is plugged into a power source it will hold the bios settings ,even with a dead battery ,battery is only for when you remove the power source

as long as the computer is plugged into a power source it will hold the bios settings ,even with a dead battery ,battery is only for when you remove the power source

This seems to be a contentious issue, (at least for me that is)... i.e. the power in a computer that is turned off. Although it may be slightly of subject, I really want to find out the truth about this. I don't want to get zapped while changing a battery for goodness sake. For me as one not experienced in such matters, it seems to hold some power at least for a little while after being turned off at the power point. How else can I explain the fact that although the power lead to the unit is physically switched OFF for an hour...the time stays correct, but when the same happens for 8 hours...the time is wrong?

This is what I have noted over the last 24 hours:
-Entered the correct time in CMOS
-Checked the correct time zone
-Rebooted several times and it held correct time and date.
-Performed a fresh cold boot next morning and instead of being AM it was PM and the time was wrong. Also the date was yesterdays date. So it looks like the time had just stopped about half an hour after I turned off the computer the nite before and continued with that time where it had stopped the next day. That would also explain the PM not being AM.

So I guess I will now take DGULLIVER's tip and replace the battery and see what happens.

Thanks so much to all who helped. When I have replaced the battery I will confirm the result on this page.

I have just joined this forum a couple of days, but the help has been awesome. The best I have experienced. I love this place:icon_smile:

How else can I explain the fact that although the power lead to the unit is physically switched OFF for an hour...the time stays correct, but when the same happens for 8 hours...the time is wrong?

While the pc has power the bios battery gets a "rest" which will allow it to put out some power for a short time. When the power is off for a while the battery will drain down below the point where it can power the bios.
You can see this effect when you have batteries in a torch that have just gone flat. Leave it off for a while and it will light the bulb up for a few seconds.

I have worked in the electronics trade for well over 20 years so I know what I am talking about.

I don't want to get zapped while changing a battery for goodness sake.

That absolutely will not happen. The battery is only 3 volts and the absolute highest voltage outside of the PSU casing is 12 volts.
It is more likely that you will zap the computer with static electricity. To avoid this you need to get your potential to that of the pc. Switch the mains off at the wall outlet but leave the mains cable attached, then remove the side panel and take hold of a bare metal part of the case for a few seconds. This will allow any static charge you may have to bleed to earth.
Do this and you and your pc will be nice and safe! :)

... Switch the mains off at the wall outlet but leave the mains cable attached, then remove the side panel and take hold of a bare metal part of the case for a few seconds. This will allow any static charge you may have to bleed to earth.

Just a bit confused as to why I need to leave the cable attached to the mains after turning it off. Why don't I just pull the whole lot out of the power point... that way I should be safe..yes?

Because the plug has an earth pin in it. The pin will stay connected to earth even when the live is switched off at the wall.

Ahh right, so the earth is grounding the machine...kewl & thanks Rik.

Morning,

Leaving plugged in a debatable subject... However I've seen DELL engineers unplug the PC and discharge it.

Good luck strikey with replacement, its an easy job to do, just make sure you ground yourself like others have said :D

Leaving the plug in is what I always do and I have repaired well over 200 pc's.

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