Repair your Dell Latitude D400 laptop's motherboard.
Your laptop's motherboard is the most important component of your laptop. It is the main printed circuit board where all components connect with the computer. When the motherboard isn't working properly, you may experience anything from power supply failure to malfunctioning hardware devices. Repairing your Dell Dimension D400 laptop's motherboard means replacing it completely. Motherboard diagnosis is costly and time-consuming. In fact, many professional laptop repair technicians will advise you to replace the motherboard in lieu of troubleshooting. Replacing the motherboard requires completely dismantling the computer.
Instructions
1. Power down the laptop, and unplug all cables and/or devices. Pull the LCD lid closed, and place the laptop so the bottom side is facing upward. Slide the battery release lever to the left. Remove the battery from the tray in the upper left corner of the laptop.
2. Remove the plastic memory cover from the center of the laptop's bottom side. It is fastened to the laptop by two Phillips-head screws. Remove both memory modules from inside the compartment. Each module is secured to its individual memory slot by two, spring-loaded retention clips.
3. Locate the modem module inside the empty memory compartment. Remove the module's retaining Phillips-head screws. Lift the modem out of its compartment, and unplug the modem's cable. Remove the modem module from the laptop. Remove the two Phillips-head screws from the hard drive in the lower right corner of the laptop. Pull the drive from its slot, and set it aside.
4. Remove all screws from the laptop's bottom side. Place the laptop so the top side is facing upward. Open the display panel as far as possible. Pry the plastic keyboard cover from the laptop with a flat-head screwdriver. This is the thin, plastic strip above the keyboard's top row of keys. Remove the Phillips-head screws fastening the keyboard assembly to the laptop. Lift the keyboard out of the laptop, unplug its ribbon cable fro motherboard and remove the keyboard.
5. Disconnect the LCD video cables from its connector in the upper left corner of the motherboard. Remove both Phillips-head screws from each display hinge. Lift the display panel from the laptop, and set it aside. Disconnect the two speaker cables from the upper left section of the motherboard. One is a black and white cable, and the other is a gold ribbon cable. Unplug the touchpad's ribbon cable from the motherboard.
6. Remove the remaining screws from the top cover assembly, and use a flat-head screwdriver to disengage the three retention latches inside the battery tray on the bottom side of the laptop. Carefully remove the top cover assembly from the laptop to reveal the motherboard's top side.
7. Loosen the Phillips-head screw fastening the black BIOS chip to the upper left corner of the motherboard. Remove the large metal shield, and its Phillips-head screws from the motherboard. Locate the cooling fan, and remove its four Phillips-head screws. Unplug its power cable from the motherboard, and lift the entire cooling assembly out of the laptop.
8. Disconnect all remaining cables and devices from the motherboard. Remove all remaining screws that fasten the motherboard to the laptop's base. Lift the entire motherboard out of the laptop's base, and set it aside.
9. Repeat this procedure in reverse to install the new motherboard, and reassemble the laptop.
Tags: Phillips-head screws, from laptop, screws from, bottom side, from motherboard, upper left