Computer fan clean has gone wrong

My fan for my laptop was getting dusty and I decided it was time for a clean. However when trying to start it back up it no longer worked. 2 weeks later I accidentally hit the power button and stayed on for a minute before dying again so I'm sure it works. The fan was still spiing at the time. Any ideas how to fix? Edit: the removed parts were the laptop back covering and the battery. That is all I can recall