My laptop keyboard sometimes works perfectly , sometimes it just fail when I press on the keys ("-0p[;/") and space key, sometimes they work sometimes not. I have tried to open the laptop, then reset it to the default by taking out the cmos battery. It was running windows 8, but after I formatted and installed win7 operating system. Last time I resetted it, it worked fine for long monthes, then now it is happening again the same issue on the same keys. I have to press several times on the same key. Toshiba p55 core i5 4200 6 gb ram. Windows 7 X64.
sometimes it just fail when I press on the keys ("-0p[;/") and space key, sometimes they work sometimes not.
Do you mean when you press certain keys different/random characters appear? I've seen a couple laptops with keyboard issues like that, I would take the proper cover/panel off such that you can access the little ribbon connector thing that connects to the motherboard, unlock the little plastic mechanism, pull the ribbon cable out and wipe it off so there are no marks/dust on it, then re-seat it back in place and lock the plastic thingy down
No,I mean those group of keys ==> 0p[;'.- when I press on those nothing shows, but if I try pressing several times it works normally, I have tried to unplug and re plug all cables even from battery, it worked a little bit, but then again this problem showed up, do you think it could be a failure on the keyboard? May changing the keyboard set might help.
I have tried to unplug and re plug all cables even from battery
If you've tried disconnecting the keyboard (similar to what is shown below) and re-connecting it and the problem persists you'll most likely need to purchase a new keyboard. It needs to be the same type of keyboard so that it fits properly in your laptop, what make/model of laptop is it?