Use a VMM & test the PSU voltages at the molex connectors for presence of 12V & 5V.
Cooling fans are 12V devices, USB is 5V, so I'd assume the machine would not work at all if it was PSU. Sound more like something on mobo is fried IMHO.
Sam Franc wrote:
My daughter's USB quit working and the fans cooling fans are not working. Would this be a mobo failure or a power supply failure? The computer is working fine in other areas, internet, programs etc. Just no USB and printing where her printer is USB. Also the computer does not recognize her USB Flash Card. The mobo is a Gigbyte MS1-SME-S2.