My iMac is dead, won't turn on...

My iMac is dead, won't turn on...

I was using my iMac, browsing and making some music. I turned it off (the back of the computer was very hot) the next day I tried to turn it on but it just won't turn on. No display and no sound, did every thing I could do except reseting the PRAM because my iMac come with a wireless keybord so I can't give any input to the iMac (Lost contact with the mac). I recon that the power supply is the problem.