I have a HP Officejet K8600 that was standing on a shelf for about three years now. When I plugged it into my computer to test it as I want to sell the printer, but don't want to sell a faulty printer. The printer's power and top cover light is flickering, the top cover is closed and I have cleaned the printer as maybe dust was at fault here. After I've cleaned the printer the light is still flickering and I can't find anything on the HP website's fault guide as to what this combination means. I've tried using different USB cables to connect the printer top my computer and I've also restarted it many times. I know a flickering power light on a first time set-up means that it's still configuring, but this light has been going on over night. What could be the cause and how will I be able to fix it?