There are a few places where you can find a replacement screen, but here is a link to one http://www.laptopscreen.com/English/mode...

You can use this guide to replace keys: Asus VivoBook Q200E-BSI3T08 Key Replacement

If you would like to clean the fan you can remove the back panel using this guide: Asus VivoBook Q200E-BSI3T08 Back Panel Replacement and then you can clean the fan using either compressed air or a small, soft brush.