Sony PCV-LX920 - Manual (Page 46)

VAIO Slimtop System Reference Manual 34
3 Lift the power supply up and out, and rest it upside down on top of
the PCI card holder.
Replacing the Power Supply
1 Lower the power supply down into position, and press down until
the power supply latches to the chassis.
2
Replace the screw that secures the power supply to the chassis.