Hey, I have an Acer V3-571G laptop which I've had since May of 2012 and some of the keys on the keyboard are playing up, specifically the shift,9 and 8. The numbers not being on the numpad. When I can get the shift working the numbers start working again as well. Usually I have to press the shift key down hard to get it working again, I've tried compressed air to clean it but no luck. Any advice or experiences would be great, Thanks.