Acer Aspire 4730Z Keyboard not working?

Borrow another keyboard as a test. If wireless, replace the batteries. Check for malware.

Do a system restore before this happened might work, hook external keyboard to the laptop if no change, if external works, there is a problem with the laptop keyboard or bad device driver.

Flip the system upside down with the lid open and shake the crumbs out of the keyboard. If this and a can of air doesn't solve the issue, you will need to replace the keyboard.

I hope I can help!

If you want to use the buttons on your keyboard to adjust your volume, just hold the "Fn" button just to the left of the windows key, and then push the "up" arrow or "down" arrow. To be clear, those are just the main arrow keys, up will turn the volume up, and down will turn it down (of course).

I hope that helps!

taken from http://www.batterycentury.com/acer-aspire-7520g-502g25mi-keyboard-p-152819.html

Acer Aspire 7520G-502G25Mi Keyboard Repair and ReplacementAre you considering laptop keyboard repair? You might think twice if you happen to be the lucky owner of a laptop, because replacing the keyboard rather than repairing it could be a lot less expensive. Laptop keyboard replacement on this particular model is very easy and takes just a few minutes. Here is a quick Acer Aspire 7520G-502G25Mi Keyboard repair tutorial with step-by-step instructions. Once you have purchased the new keyboard, all you need to replace the old with the new is a screwdriver and something plastic, flat and thin like a credit card or guitar pick.
Step one: Remove the two screws from the bottom of the computer that are holding down the Acer Aspire 7520G-502G25Mi Keyboard bezel. The bezel is the bar that sits right above all the function keys.
Step two: Turn the computer over, open the cover and insert the credit card or guitar pick between the bezel and the laptop screen. The bezel has pegs that sit in holes, you need to slowly pry up the bezel. It will make a bit of a popping noise as it is removed.
Step three: Now hold on to the laptop keyboard from the end closest to the screen and gently pull it away from the touch-pad end and flip it over. You will see the ribbon attached to the underside of the Acer Aspire 7520G-502G25Mi Keyboard. There is a little plastic connector holding the ribbon to the computer. To unlock it, carefully pull up on the two tabs; one located on each corner of the connector. Be very gentle when you do this as this is the one part that gets broken the most often when changing a keyboard. The ribbon cable will now be released.
Step four: Carefully pull the ribbon out of the connector and remove it along with the entire Acer laptop keyboard.
Final step: To insert the new Acer Aspire 7520G-502G25Mi Keyboard, place the board face down so you have easy access to the ribbon. Make sure the keyboard is lined up so when you flip it back over the keys are in the correct position. Keep the ribbon straight at all times; twisting it could damage it. Place the ribbon in the connector; it only goes in one way. Once in place, push down on the connector tabs to lock it. Now flip the keyboard over and slide it down toward the touch pad and take the bezel and line the pegs up with the holes and push it in place. Then turn the computer over and replace the two screws you removed from the bottom. You can now power on your computer and see if the Acer Aspire 7520G-502G25Mi Keyboard works. If it is not working, more than likely the ribbon was not inserted properly.

Aspire D250.....

Hold down function key fn (lower left on keyboard) and tap F7 key once..

To take the keys off, gently pull up on the top side of the keys until they snap off. Just push them down again and they'll snap back on.

when upower up press F8 key then enter in safe mode.then clik on administrator
then u enterin winxp.then reset password or blakn
then try in noraml winxp.

You probably activated the "Num Lock" accidently. Just hold down the FN and look for the key that says "num lock" Now you should have your keyboard back and the numbers will just type when you hit the numbers key. I did this to myself yesterday!

if it is new & under warranty, best bet is Acer service center.