• If the voltage supply range in your local country or region is 200–240 V ac, set the voltage-selectionswitch to 230 V.8. Install the new power supply assembly into the chassis so that the screw holes in the power supplyassembly align with those in the chassis.9. Install and tighten the four screws to secure the power supply assembly.Note: Use only screws provided by Lenovo.10. Reconnect the power supply assembly cables to the system board and each of the drives.11. Secure the power supply assembly cables with the cable clips and ties in the chassis.What to do next:• To work with another piece of hardware, go to the appropriate section.• To complete the installation or replacement, go to “Completing the parts replacement” on page 131.Replacing the microprocessorAttention:Do not open your computer or attempt any repair before reading and understanding the “Important safety information”on page 1.CAUTION:The heat sink and fan assembly might be very hot. Turn off the computer and wait three to fiveminutes to let the computer cool before removing the computer cover.This section provides instructions on how to replace the microprocessor.To replace the microprocessor, do the following:1. Remove all media from the drives and turn off all attached devices and the computer. Then, disconnectall power cords from electrical outlets and disconnect all cables that are connected to the computer.2. Remove the computer cover. See “Removing the computer cover” on page 90.3. Lay the computer on its side for easier access to the system board.4. Locate the system board and disconnect all cables connected to the system board.5. Remove the heat sink and fan assembly. See “Replacing the heat sink and fan assembly” on page 103.Note: Place the heat sink and fan assembly on its side so that the thermal grease on the bottom of itdoes not get in contact with anything.106 ThinkCentre M73 Hardware Maintenance Manual
