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# System Upgrades

Dell™ Latitude™ C840 Service Manual

Memory Modules

Modem Daughter Card

Mini PCI Card

## Memory Modules

| NOTICE: Disconnect the computer and any 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 Memory Module/Modem Cover

1 | M2.5 x 20-mm screw

1. Follow the instructions in "Preparing to Work Inside the Computer."
2. Remove the M2.5 x 20-mm screw from the memory module/modem cover.
3. Disengage the metal tabs at the opposite end of the cover.

1 | DIMM B
2 | memory module sockets (2)
3 | DIMM A socket
4 | modem daughter card
5 | metal tabs (2 per socket)

### Removing the Memory Modules

1. Remove the memory module/modem cover.
2. To release a memory module from its socket, spread apart the tabs at each side of the module until the module pops up slightly.
3. Lift the memory module out of its socket.

### Replacing the Memory Modules

1. If you only have one memory module, install it in the socket labeled "DIMM A." Install a second memory module in the socket labeled "DIMM B."

| NOTE: Memory modules are keyed to fit into their sockets in only one direction.

1. Insert the memory-module edge connector into the socket slot at a 45-degree angle and press the module firmly into the slot.
2. Pivot the module down until it clicks into place. If you do not hear a click, remove the module and reinstall it.
3. Insert the metal tabs on the memory module/modem cover into the bottom case, rotate the cover down, and replace the M2.5 x 20-mm screw.

## Modem Daughter Card

### Removing the Modem Daughter Card

| NOTICE: Disconnect the computer and any 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.

1. Follow the instructions in "Preparing to Work Inside the Computer."
2. Turn the computer over and remove the memory module/modem cover.

1 | modem daughter card
2 | M2 x 3-mm screw

1. Remove the M2 x 3-mm screw that secures the modem daughter card to the system board.
2. Use the pull tab to pull the modem daughter card straight up out of its connector.

| NOTICE: Do not pull on the modem cable. Pull the connector on the end of the cable to disconnect the cable.

1. Disconnect the modem cable from the modem daughter card.

### Replacing the Modem Daughter Card

| NOTICE: The cable connectors are keyed for correct insertion. Do not force the connections.

1. Connect the modem cable to the modem daughter card.
2. Use the screw and boss holes at opposite corners of the modem daughter card to align the card, and press the card into its connector on the system board.
3. Install the M2 x 3-mm screw that secures the card to the system board.
4. Replace the memory module/modem cover.

## Mini PCI Card

You must remove the optional Mini PCI wireless modem (if installed) before the system board can be removed. A wireless modem card must be connected to the internal antenna of the computer.

| 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.

Mini PCI Card Cover

1 | M2.5 x 20-mm screw

### Removing the Mini PCI Card

1. Follow the instructions in "Preparing to Work Inside the Computer."
2. Remove the M2.5 x 20-mm screw and then remove the Mini PCI card cover.
3. To release the Mini PCI card, spread the metal securing tabs until the card pops up slightly.
4. Disconnect the card from the internal antenna.
5. Lift out the card and disconnect any attached cables.

### Replacing the Mini PCI Card

1. Align the Mini PCI card with the socket at a 45-degree angle, and press the Mini PCI card into the socket.
2. Connect the internal-antenna cable to the primary-antenna connector on the card.

| NOTICE: The connectors are keyed for correct insertion; do not force the connections.

1 | internal-antenna cable
2 | primary-antenna connector on card

1. Pivot the Mini PCI card down until it clicks into place.
2. Replace the Mini PCI card cover and the M2.5 x 20-mm screw.

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