This video shows how to replace the 4G WWAN card on Latitude 5550/Precision 3590/Precision 3591. Before you begin, turn off the computer and disconnect all the attached peripherals. Ensure that you always use ESD protection when working inside the system. To enter Service Mode, press and hold the B key on the keyboard, and then press the power button.
Now, the computer will boot up and the Owner Tag information is displayed. Press any key to proceed. The computer will emit three short beeps and shut down. To begin Loosen the eight captive screws that secure the base cover to the palm-rest assembly. Using a plastic scribe, pry open the base cover from the recesses near the hinges. Lift the base cover off the palm-rest assembly. Ensure that your computer is in Service Mode.
If your computer is unable to enter Service Mode, disconnect the battery cable from the system board. Turn over your computer and open the display to access the power button. Press and hold the power button for five seconds to ground the computer and drain the flea power. Using a plastic scribe, pry open the 4G WWAN-card shield that secures the 4G WWAN card to the palm-rest assembly. And lift the shield off the card.
Remove the screw that secures the WWAN-card bracket to the card and palm-rest assembly. And lift the bracket off the card and palm-rest assembly. Now, disconnect the antenna cables from the card. Remove the card from the slot on the system board. You have successfully removed the 4G WWAN card. Now, let’s install the 4G WWAN card. Connect the antenna cables to the card.
Align the notch on the card with the tab on the card slot. And insert the card at an angle, into the slot. Now, Align the screw hole on the bracket with the screw hole on the card and palm-rest assembly. Replace the screw that secures the wireless-card bracket to the card and palm-rest assembly.
Then, Align and place the WWAN-card shield on the 4G WWAN card. Make sure you reroute the antenna cable. Next, since the battery is not a pre-requisite if you have disconnected the battery cable, ensure to connect the battery cable. Align the screw holes on the base cover with the screw holes on the palm-rest assembly, and then snap the base cover into place. Tighten the eight captive screws that secure the base cover to the palm-rest assembly. If you need more information or assistance, go to: Dell.com/Support
