My computer won't boot

[hak123]

so today i went on my computer and when i booted it i heard this sound which sounded like an explosion. then i went and cleaned the fan. then i try to turn on the computer but it didnt turn on. do you think its the power supply or the motherboard, or what you think is the problem

 

[mailpup]

You could take a look at the motherboard to see if there are any burn marks anywhere or perhaps a capacitor exploded.

If you are not getting any power to anything, it could be the PSU too. Do you have access to another for testing purposes?