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A few days ago, I went out of town, and I thought it'd be wise to pull the plugs for my TV, PC, consoles etc., to avoid having anything be on standby and consuming (i know, very small amounts of) power.

Now I've just come back home, plugged everything back in, and powered it up. That is, except my desktop computer...

I've experienced this problem before in different situations, e.g. when unplugging the computer and changing some parts. Every time the computer has been completely without power for some time, it takes some time, after it has been plugged back in, before it will actually boot up. During that waiting period, nothing happens when I push the power button. I then leave it, and suddenly it boots up as if nothing happened. Actually, while writing this on my netbook, the desktop has booted up by itself.

Why is that? :-)

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Replace the motherboard battery. I'm not exactly sure why, and it may be hardware related because other motherboards may well boot properly and right away even with a flat battery, but the symptoms described point to a flat mainboard battery. – Ярослав Рахматуллин Nov 5 '12 at 2:27
up vote 1 down vote accepted

Could just be your CMOS battery - which you can easily replace for the cost of a new "Button" battery.

The general symptoms are either a really long time to boot (since BIOS settings are not saved and much be re-created each boot) or just not boot at all.

I have experienced this myself; however, to provide more validity - here is an eHow article.

There are other symptoms listed; however, these seem to be the most common for me:

A dead or dying CMOS battery may cause your computer to take a long time to boot up. This is because your computer has to actually recreate the BIOS settings from scratch every time you reboot. Figuring out the number and location of hard drives, the available amount of memory and other information necessary for booting may cause your computer to delay significantly. This can also cause the computer to run at the wrong speed, since the BIOS settings aren't retained. A computer with a bad CMOS battery may refuse to boot entirely.

Replacing this is generally pretty easy, but if you have any troubles - feel free to post your Mobo model and I can help out.

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cool, I'll try changing the battery. Txh! =) – Phazyck Nov 5 '12 at 8:39
Sure, let us know the outcome! – nerdwaller Nov 5 '12 at 12:50
Hmm... Changing the battery didn't seem to do much. However, the problem ain't that big a deal... :-/ – Phazyck Jan 8 '13 at 19:51
Could be a grounding issue then, try unplugging it from the wall and hold the power button a while to dissapate. Verify that no stray wires and such are around (or splits in any) and try booting again. I have had a grounding issue in one case before that was semi-similar. – nerdwaller Jan 8 '13 at 20:17

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