Back to Contents Page

# Microprocessor Module

Dell™ Latitude™ C840 Service Manual

| NOTICE: Disconnect the computer and attached devices from electrical outlets and remove any installed batteries.

| NOTICE: To avoid ESD, ground yourself by using a wrist grounding strap or by periodically touching unpainted metal on the computer.

### Removing the Microprocessor Module

1. Follow the instructions in "Preparing to Work Inside the Computer."
2. Remove the keyboard.
3. Remove the hinge cover.

| NOTICE: To ensure maximum cooling for the microprocessor, do not touch the heat transfer areas on the microprocessor thermal-cooling assembly. The oils in your skin reduce the heat transfer capability of the thermal pads.

1. Remove the microprocessor thermal-cooling assembly.

| NOTICE: When removing the microprocessor module, pull the module straight up. Do not bend the pins.

1. Remove the microprocessor module.

| NOTICE: To avoid damage to the microprocessor, hold the screwdriver so that it is perpendicular to the microprocessor when loosening the cam screw (see "Microprocessor Cam Screw").

1. Loosen the cam screw that secures the microprocessor module. The location of the screw and the rotation direction may vary with the socket manufacturer; look for small icons indicating open and locked positions.

Microprocessor Cam Screw (Example)

| NOTICE: Hold the microprocessor down while turning the cam screw to prevent intermittent contact between the cam screw and microprocessor.

1 | cam screw
2 | perpendicular screwdriver
3 | processor die (do not touch)

1. Use the microprocessor extraction tool to remove the microprocessor module.

### Replacing the Microprocessor Module

| NOTICE: If you received a flash BIOS update floppy disk or CD with the replacement microprocessor, you must update the BIOS after replacing the microprocessor module.

| NOTICE: Proper seating of the microprocessor module does not require force.

| NOTICE: A microprocessor module that is not properly seated can result in an intermittent connection and subsequent failures.

1. Align the pin-1 triangle on the microprocessor with the pin-1 triangle in the socket, insert the microprocessor into the socket, and move the microprocessor around slightly until you feel it settle into the socket.

When the microprocessor module is correctly seated, all four corners are aligned to the same height. If one or more corners of the module are higher than the others, the module is not seated correctly.

| NOTICE: Hold the microprocessor down while turning the cam screw to prevent intermittent contact between the cam screw and microprocessor (see "Microprocessor Cam Screw").

1. Tighten the cam screw.

| NOTICE: Do not over- or undertighten the screw. Tighten the screw until the screw indicator points to the "closed" or "locked" indicator on the socket.

1. Replace the microprocessor thermal-cooling assembly.

Closing the Microprocessor Retaining Clip

1. Close the microprocessor retaining clip.
2. To latch the clip, insert a flat-blade scribe into the latch mechanism and pivot the top of the scribe away from the clip.

Back to Contents Page