Disconnect the power-supply cables 1, 2, and 3 from the system-board connectors, all adapter cards (some models) and from all drives.
Remove the power-supply cables from the cable clips and ties.
Remove the four screws at the rear of the chassis that secure the power supply.
Depress the power supply latch 1. Slide the power-supply assembly toward the front of the computer, remove it from the chassis.
Install the new power-supply assembly into the chassis so that the screw holes in the power-supply assembly align with those in the chassis.
Note: Use only the screws provided by Lenovo.
Install and tighten the four screws at the rear of the chassis to secure the power-supply assembly.
Ensure that the power supply is the correct replacement. Some power supplies auto sense the voltage, some power supplies are voltage specific, and some power supplies have a voltage selection switch. If there is a selection switch use a ballpoint pen to slide the switch, if necessary.
Note: For models that have a switch:
If the voltage supply range is 100-127 V ac, set the switch to 115 V.
If the voltage supply range is 200-240 V ac, set the switch to 230 V.
Reconnect all the power supply cables to the drives, adapters, and the system board. Make sure to reconnect power to the graphics cards that require an additional cable.