Compaq mini 110

Stock components

Ubuntu 12.04

The good:

*HDD LED is flashing

Keyboard+mouse are functional

External ports are functional

Battery is charging

Wireless LED is on*

The bad:

*Fan is not spinning

No display

No POST errors being emitted

Out of warranty*

Solutions attempted:

*hard reset

connecting external monitor

pressing f8

pressing f10

Reseating HDD

cleaning with compressed air

Reseating battery*

The computer occasionally works if its been untouched for several weeks but then it freezes and i can't boot it up again.

Does anybody know what could be the problem?

UPDATE: after leaving it running overnight, the fan has started spinning again but it didn't fix the problem.