The problem could be anywhere along the power ciruit, or even farther up the line. It could be any of the inverter components or perhaps a logic circuit. It's probably an IC somewhere, but could be anything: diode, cap, resistor, fuse?? Or, it could be an entire circuit that fried.
The point is that, without a thorough understanding of electronics and diagnostics (as well as a schematic diagram of the printer's circuitry) a self-repair is probably doomed to failure.