Some keys on keyboard don’t work

An Acer Aspire keyboard started out with the spacebar use occasionally jumping back to the middle of text written. Today some keys work and some don't. Some type two or three characters with one keystroke. I went to settings, and all seems well there. Another forum suggested the number lock was on. Checked that and some of the double characters stopped, but many on the qwerty row don't work and especially the backspace and spacebar don't work. Please help before I pop the back off the damn thing!! Or worse, buy a new laptop when I don't have to!