if the fans are on now check that nothing is clogging the power supply. see if there a 3 party program to check the units fan and temp. if the fan is on check the power supply temp see why it running hot. most newer power supply fans should not be hurd. if you can hear it the fan can have gone bad or somoehow you pushed it into the power supply or case. with the pc off and unplugged see with your finger if the fan moving fine or it bound.