I recently opened up a Toshiba Satellite c55-a-5100 laptop, cleaning out the CPU fan/heatsink and re-applying new (Cooler Master high Performance thermal compound kit, possibly conductive?) thermal paste. I did not take the CPU out of its socket. I also cleaned the top of the chipset, otherwise nothing else was majorly tinkered with. On putting everything back together (twice now), the power button comes on, but I'm met with a blank screen. I've tried connecting to an external monitor with no luck either. The laptop fan doesn't spin at all now.