I recently disassembled my hp pavilion dv7 to clean out the fan due to overheating, now it won't boot, all I get is hard disk error, press f2 for system diagnostics, run system diagnostics, hard drive is fine. Only error is battery failure, the battery hasn't been charging for a little bit now.. I did a hard reset, same problem, took it apart, double checked everything, same problem. How do I get this stupid thing to boot or how can I back it up without booting it up, PLEASE HELP