Hello, what's the model of your computer? Any beep codes? Does the fan spin When you hit the power button?
If you hit the power button and the fan spins, your CPU/RAM/Bios may be failed. If you confirm bios is dead, you need a new motherboard.
If nothing happens, most likely because of a dead motherboard. But I see you are low on money, go to amazon/ebay and see if there's still some motherboard that are compatible with your cpu.
If CPU/RAM died use the same solution that i said for the dead motherboard, i think it doesn't costs you for over $50.