How to Fix a Laptop Power InputPosted by monsterguide
How to Fix a Laptop Power Input
Besides extra battery chargers, your laptop charges the battery through the DC jack found at the side of the laptop case. Often, it is not the battery or the charging unit that becomes a problem, but the DC jack has come loose. While laptop repair is definitely not for beginners, repairing the DC connector socket is a task that you can do at home, provided you have the skills and the tools necessary to do the job.
If you carelessly yank out the DC adapter socket from the notebook’s DC jack, you run the risk of snapping the DC jack from the motherboard. DC jacks from laptops are usually damaged because of physical stress, or when the jack is connected to the motherboard with a cold solder. You may need to repair the DC jack if:
- Your adapter works fine, but it doesn’t charge the battery or power the laptop at all.
- You need to wiggle the DC jack to supply power to the laptop from an electrical socket.
Warnings and Safety Reminders
Repairing a laptop, especially a problem as complicated or as technical as repairing power circuits, requires expert knowledge in computer electronics. Do not, under any circumstances, repair your laptop if you do not know how to go about the repair job. If you’re not sure what you’re doing, take your defective device to a qualified technician or the manufacturer’s service center. The cost may seem a bit high, but it’s better than having to buy a new one because your haphazard repair job didn’t work.
Here are some things you should also keep in mind:
- Always work on an anti-static mat or a tile or hardwood floor. Do not work on static surfaces like rugs or carpet.
- Remember to turn off the laptop before disassembling it. Remove the DC adapter from the wall socket and take out the battery.
- Never tinker with other parts in your laptop that are not recommended or labeled as user serviceable.
- Always work in a clean environment.
Here are the tools you need to repair your laptop DC jack:
- Screwdriver set
- Soldering iron or soldering station
- Resin-core silver solder
- Desoldering pump
- Pure distilled alcohol (99% alcohol, not 70% rubbing alcohol)
- A new toothbrush
- Pen knife
Preparation and Disassembly
- Heat the soldering iron to 800 degrees Celsius.
- Remove the screws holding together the base of the laptop case. Make sure to photograph or take notes of the screw positions and the laptop assembly.
- Carefully remove the motherboard from the chassis. Do not bend or force the motherboard out of the chassis.
- Blow off dust and other debris with your own breath. Do not use an electric fan or a blower.
- Place the motherboard on an anti-static mat or a clean surface covered with anti-static bags.
Removing the DC Jack
- The DC jack looks like a small silver box. Most laptops have this piece located on the top right edge or corner of the motherboard assembly.
- Inspect the jack from all sides, without taking it out of the assembly. You may notice that the soldered contacts may be misaligned, or haphazardly soldered. Cold solders, insufficient solder, or excessive solder may cause the power problem on your laptop.
- Now you need to dissolve the old solder. A hot soldering iron and the desoldering pump would be fine for the job, although it also helps to add a bit of hot solder to the old soldered contacts to make the metal and resin flow.
- Pump out as much as you can of the old solder.
- To remove the jack, dissolve the existing contacts with the soldering iron. With as little force as possible, lift up the jack from the motherboard. Be careful not to remove the copper sleeve inside the jack.
- Now that the jack is out, you may notice that the receptacle on the circuit board is messy-looking because of flux and old solder. Carefully clean out the flux with a toothbrush. While this step is not necessary, it makes your motherboard much cleaner. Another advantage to cleaning out the flux is that you don’t have a problem with flux disrupting the power flow.
Replacing the DC Jack
- Start by cleaning out the contacts of the DC jack with a pen knife. Be careful not to scrape too deeply or to dislodge the contacts from the jack.
- Apply a fresh coat of solder on the contacts. Do not use more solder than necessary.
- Apply a layer of solder on the DC jack contacts on both sides of the motherboard. Make sure that you only use enough solder to coat the surfaces of the contacts.
- Attach the DC input jack on the motherboard.
- Solder the contacts and pins with a neat solder job. Do not use excessive amounts of solder. Use just enough solder to cover the contact pins.
Once you have replaced the DC jack and reassembled the laptop, it’s important to test the jack. Be very careful when working the electricity; if you did not do a good job of soldering the contacts and replacing the DC jack, you may run the risk of short-circuiting the entire unit.
Replacing the DC jack is a very sensitive operation that should only be done by experienced electricians or computer technicians. If you’re not sure about what to do, it’s best to check your warranty for instructions on where you should take the laptop for repair.
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