What to Do If Your Computer Doesn’t Turn On
By Gabriel Torres on April 22, 2008 Page 4 of 7

Step 3 – Clearing the CMOS Memory

The next step is to clear the CMOS memory, which is a small memory located on the motherboard in charge of storing your computer configuration. This is done by changing the position of a jumper or by shorting two pads or two pins on the motherboard with a flat-tip screwdriver. The exact location of this jumper, pads or pins depends on the motherboard and you must see the exact location on the motherboard manual (usually they have “Clear CMOS”, “CCMOS” or “CLRTC” written next to them). On the pictures below we give some examples.

Clear CMOS
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Figure 1: Clear CMOS jumper (you will need to change its position).

Clear CMOS
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Figure 2: Clear CMOS pins (you will need to short them with a flat-tip screwdriver).

Clear CMOS
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Figure 3: Clear CMOS pads (you will need to short them with a flat-tip screwdriver).

The procedure is always the same: with the computer turned off (i.e. with the computer power cord removed from the wall) move the position of the jumper or short the two pads or two pins with the screwdriver and hold it for two seconds, then move the jumper back to its default position and then turn on the computer again.

If this step didn’t solve the issue – i.e. if your computer is still not turning on – then go to the next step. If clearing the CMOS memory solved your issue, you will need to do two things. First you will need to put all parts from your computer back in place. Second you will need to enter the motherboard setup and reconfigure it. Your computer will be complaining that the CMOS memory was erased, so you will need to press F1 to enter setup and reconfigure it.


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