Boot error Keyboard is locked unlock keyboard

March 17, 2010 at 07:45:49
Specs: Windows XP
My dad's PC started displaying an error message "Keyboard is locked - unlock keyboard" when booting up on the POST screen.

The motherboard is an ASUS P4S533 with Award BIOS.
I've tried 3 different PS/2 keyboards and a USB one just in case. I've removed the CMOS battery to reset the BIOS, but now it boots straight to the BIOS setup screen. Since the keyboard still doesn't work there's nothing I can do in there.
He says this came on suddenly - he booted down one night and it was fine, the following day he got the error message.

Does anyone have any idea what may be wrong? Is the motherboard broken or is it (hopefully) something nice and simple?

Thanks :)

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March 17, 2010 at 08:26:25
NOTE that Asus desktop mboards that have headers for both USB ports and one or more firewire port have identical headers for both of those. If you connect USB port wiring to a firewire header, or firwire port wiring to a USB header, nothing happens until you plug something into the mis-wired port, BUT when you DO plug something into the mis-wired port, all hell breaks loose !!! - whatever you plugged in and the circuits for whatever header are damaged in a short time, and the mboard can also be damaged !
The two types of headers have different colored plastic at their base - make sure you do not have wiring for a port connected to the wrong header ! See the mboard manual !

Desktop mboards often have a pair of pins for a keyboard lock switch on a header on the mboard. Most desktop cases do not have such a switch - if the case has a switch, it's either a typical round chrome one you insert a tubular key in on the front of the case, or it's a switch inside the case that is locking the keyboard when the side panel is removed. If there is nothing connected to the pins, the use of the keyboard is not locked. There is no setting in any bios I've seen regarding the keyboard lock setting, and even if there was, the bios default would be for the keyboard to NOT be locked. and removing the Cmos battery would reset that to the default.

Your problem would probably be either that
- the mboard is damaged
- the power supply is failing, which may have already also damaged the mboard.

Mboards sometimes have had electrolytic capacitors installed on them that were improperly made, and those fail eventually and can produce all sorts of weird symptoms.

Open up your case and examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .

This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:

What to look for, mboard symptoms, example pictures:
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.

Pictures of blown capacitors, other components, power supplies, Athlon cpu's, etc.:

Similarly, power failure events, or power spikes or surges, can damage the mboard or anything connected to it - you may or may not see physical evidence of that. If a power failure event was caused by a lightning strike on the power grid, that can damage anything on the computer, even if you have everything connected to the computer that plugs into AC power directly or by means of an AC to DC power adapter plugged into something decent that protects against power spikes and surges.

Failing power supplies are common and can cause your symptoms.
If the power supply is not putting out +5v, or if what is supposed to be +5v is too low, the USB and PS/2 ports (and serial ports and a parallel port and optical drives and a floppy drive) cannot work or cannot work properly, any you have have other symptoms.
If the PS is/was putting out too much of what is supposed to be +5v , that will damage drives, cards, or components or the mboard if that has gone on too long.
Check your PS.
See response 4 in this:

If it is failing, you can usually replace it with any decent standard sized standard ATX PS with the same capacity or greater.

Standard (PS/2) power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.

Don't buy an el-cheapo PS.
See response 3 in this:

Your power supply must have at least the minumum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD ! )
If that info is not in the ad for the video card, you can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements. Some power supplies have two or more +12v ratings - in that case, add those ratings to determine the total +12v current capacity.

If you're a gamer....
In most if not all cases, the max capacity rating of the PS is an intermittant rating. It's recommended that you do not load your PS to any more that 80% of that rating if you are going to be using something that puts a constant load on it, such as playing a recent game for hours on end. In that case, you multiply the min capacity stated for the system with the particular video chipset on the card by 1.25 to find the min. capacity of the PS you should get.

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March 17, 2010 at 21:27:55
Check my # 2 here:

You're not really green until you're soylent green.

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March 18, 2010 at 02:41:22
Thanks for the replies :)

There's no lock switch or any connectors for one on the motherboard.
I've had a look at the motherboard and there's no physical signs of anything blown or otherwise damaged.
I've tried swapping the power supply with one from a working PC but that made no difference.

I'm beginning to suspect that my dad's going to have to get a new motherboard or a new PC.

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March 18, 2010 at 13:59:26
As I mentinoned in the link above, a blown fuse won't look blown and may be hard to find. Of course it could be other things too but that seems to me to be the most likely.

You're not really green until you're soylent green.

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