Lenovo ThinkCentre 3231 Hardware Maintenance Manual page 99

3. Lay the computer on its side and remove the four screws at the rear of the
chassis that secure the power supply.
Figure 9. Removing the retaining screws for the power supply
4. Remove the old power supply from the chassis.
5. Ensure that the power supply is the correct replacement. Some power supply
automatically sense the voltage, some power supply are voltage specific, and
some power supply have a voltage-selection switch. If your computer has a
voltage-selection switch, ensure that you set the voltage-selection switch of the
new power supply to match the voltage available at your electrical outlet. If
necessary, use a ballpoint pen to slide the voltage-selection switch to a
different position.
v If the voltage supply range in your local country or region is 100–127 V AC,
set the switch to 115 V.
v If the voltage supply range in your local country or region is 200–240 V AC,
set the switch to 230 V.
6. Install the new power supply into the chassis so that the screw holes in the
power supply align with those in the chassis.
7. Install the four screws to secure the power supply.
Note: Use only screws provided by Lenovo.
8. Reconnect the power supply connectors to the system board.
9. Reconnect a power supply connector to each of the drives.
10. Go to "Completing the FRU replacement" on page 122.
Chapter 8. Replacing FRUs - Tower computers
93