Replace the power supply when the laptop has intermitent power.
When you need to repair the power supply in a Dell laptop, you need to repair the DC jack. In most cases, this is a repair when the laptop does not turn on when plugged into the power outlet, but does when the battery is charged, or when you have intermittent power to the machine. If you constantly have to wiggle the power connection on the back of the laptop, you need to replace the power supply.
Instructions
Disassembly
1. Disconnect the laptop from the power outlet and disconnect any external devices or other cables from the laptop. Turn the laptop over, remove the battery and remove all the screws from the bottom of the laptop. Keep them in small paper cups so you can replace them easily. Remove the plastic covers, RAM and the Wi-Fi card. Turn the computer to the side and slide out the CD/DVD device.
2. Turn the laptop back over face-up but place the rear of the machine toward you. Remove the screws from the plastic hinges with the flat edge of a precision screwdriver. Face the computer front to you and open the screen as far back as it will go. Pull the plastic screen hinges and attached plastic power button up until the front plate comes off. Refer to your computer manual to make sure the power plate for your model is removed in this way. Some power plates do not require you to lift the plastic hinges but just the plate above the keyboard.
3. Remove the screws that hold the keyboard and lift the keyboard from the top corners. Raise the data cable lever about 1 millimeter. This lever does not come off just raises to unlock the data cable. Pull the cable out and remove the keyboard.
4. Locate the side bay for the hard drive. This will be a rectangular plastic cover on the side. Remove the screw that holds the cover from underneath the laptop, if you haven't already. Slide the hard drive assembly out and set it aside.
5. Remove the screws that hold the interior hinges to the laptop and disconnect the screen connectors. Place the screen to the side. Turn the bottom assembly on all sides and remove any screws that you find.
6. Insert the flat edge of a precision screwdriver in the seam of the plastic top and bottom cover of the bottom assembly. Pry the plastics apart gently starting at one corner. You will hear the interior plastic clips start to open. Disconnect the touchpad cable from the motherboard and set the upper plastic assembly away. Remove the screws that hold the heatsink to the processor. Set the heatsink aside. Remove the screws from the motherboard that hold it to the bottom plastic cover.
Power Jack Repair
7. Turn the laptop motherboard over bottom side-up on your work surface with the DC jack in front of you. Add new fresh solder to all three contacts that hold the DC jack. This makes the old solder become loose and makes it easy to remove. As you are heating a contact, remove the solder using a desoldering pump. Do the same with the other two contacts. Remove as much solder as you can.
8. Place your thumb and third finger on the jack and wiggle it back and forth to start removing it. It may not come off on the first time. Heat the contacts again with the soldering iron and continue to wiggle the jack until it comes off.
9. Remove old flux from the terminals using a toothbrush dipped in alcohol. Gently brush away the flux from the terminals only.
10. Replace the old power supply DC jack with a new jack made for your Dell model. You can purchase these at local computer store or at an online computer store like Geeks, New Egg or eBay (See Resources.)
11. Place the new jack on a folded cloth on the table with the pins facing upward. Place the motherboard upside down over the jack and allow the jack terminals to insert into the motherboard. Soldering the jack in this way will ensure a good pin connection. Apply fresh solder to all the power jack terminals on this side of the motherboard. Turn the motherboard over and apply solder to this side of the terminals. Allow the solder to dry and return the motherboard in its correct position to the laptop. Refasten to the bottom plastic and replace all other parts in the reverse order from which you took it apart.
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