A laptop without a motherboard battery will display the wrong time.
When your Dell Latitude C400 laptop is powered off it uses a motherboard battery, also known as the CMOS or RTC battery, to store the system time and operating system information. If your laptop is always displaying the wrong time or won't load the operating system properly you must manually replace the motherboard battery. To reach the battery you have to take apart a large portion of the C400 laptop, which can make the process difficult for the novice computer user.
Instructions
1. Shut off the Dell Latitude C400 and close the display lid. Unplug the C400's power adapter cable and any other connected cables. Turn the Latitude laptop upside down.
2. Push the battery slide bar to its unlocked position. Remove the battery from the C400's battery bay. Locate the plastic hard drive door at the lower right end of the laptop.
3. Remove the screw holding the door in place with a Phillips screwdriver. Slide the hard drive to the right and pull it out of the Dell C400 computer.
4. Remove the six palm rest securing screws located at the top edge of the C400's case. Remove the two palm rest securing screws at the bottom edge of the case, then the two display assembly screws at the lower left and lower right corners.
5. Turn the C400 over, then open the display lid 180 degrees so that the laptop is laid out flat. Hold down the "F4" and "F5" keys to pop up the release slot at the left edge of the keyboard.
6. Slide the end of a flat-head screwdriver into the release slot. Pull the slot upward to disconnect the plastic cover located above the C400's keyboard.
7. Remove the four securing screws located along the top edge of the C400's keyboard. Disconnect the keyboard cable, and pull the keyboard off the laptop.
8. Remove the two screws at the upper left end of the C400's motherboard that hold the display screen's cable in place. Disconnect the cable, then pull the display screen off the C400's case.
9. Remove the six screws around the edges of the palm rest that hold the palm rest unit to the C400's case. Pull the palm rest off the laptop.
10. Locate the battery, which is positioned at the lower right end of the motherboard below the black system fan. Unplug the battery's cable, then pull the battery off its motherboard port.
11. Push the new motherboard battery onto the port and attach its cable. Reassemble the C400's palm rest, display screen, keyboard, hard drive and battery.
Tags: palm rest, C400 case, display screen, hard drive, lower right, motherboard battery, securing screws