My Asus X200CA Notebook appears to have related problems. It started with the letter B suddenly not working, then coming good after weeks but losing battery charging functionality (0%, charging) about the same time, then my wireless mouse would not work but a wired mouse did. I was about to throw it out, but tried it a couple of days later and is working perfectly so is back in use. About the same time I've lost an array of letters and numbers so I'm using the OSD to write this. I have tried sfc / scannow and deleting drivers . Win7. Any ideas?