LEARNING OBJECTIVE – Learn how to solve laptop power problems
Typical faults: laptop does not power on, power is intermittent
Common symptoms of power problems are:
- Laptop wouldn’t power up unless the power lead is held in one position
- When the power lead is wiggled, it makes or loses contact
- Laptop only runs on battery power even power cable plugged in
- Laptop suddenly changes from battery to AC power
- Intermittent charging or battery wouldn’t charge
- The pin in the centre of the jack is loose, pushed in, broken or missing
- The whole connector is loose, pushed in, broken or missing
- When power is connected sparks come out or smells of burnt out
- The battery charge light wouldn’t come on (lights up) when power is connected
- The battery charge light (LED) flickers when the tip of the AC adapter moves
- The screen flickers between bright and dim when the tip of the charger moves
- “Scratching” sound is coming from the DC socket when the power is connected
- Jack broken because excessive pressure applied when plugging in or someone tripped over the power lead or laptop dropped and fallen down on socket while plugged in
- Your laptop will not power up at all (a dead laptop)
Any one of these typical symptoms can be categorized into 2 simple categories:
The laptop is dead.
- Check power to the adapter and from the power jack
- Remove the hinge plate cover or area where the power button is located and press the micro switch underneath with the power jack plugged in. If the laptop comes on then check the cable connections to the button pad.
- If the laptop remains dead then strip the laptop down and check the power jack for dry or broken solder joints. Carry out the best repair as per the instructions you received on the course, this will be to either replace the power socket with a new one or re-solder the existing connections.
The laptop power is intermittent
- Check power to the power jack, wiggle the jack and cable to test for a break. Repair or replace as deemed the best solution. Remember “time is money”.
- If power through the jack is consistent then strip the laptop down and test for dry / broken solder joints around the power socket. Carry out the best repair as per the instructions you received on the course, this will be to either replace the power socket with a new one or re-solder the existing connections.
More recent laptops have the power socket separate to the motherboard and it may be cheaper to replace this part rather than enact a repair. Carry out your usual continuity tests on the jack even on this smaller board first to pinpoint the power socket circuit as the problem.
If you have successfully tested the voltage through the power jack then visually check the components immediately around the power jack. If you see what may be a dry or broken solder joint then only attempt a repair on these if you feel confident enough to do so.
You will most likely see a lot of power problems relating to laptops if you decide to work for yourself. You should practice your soldering technique and become as proficient as you can.
When testing a power jack use the continuity part of your multi-meter. Buy a brand that sounds a beep when the circuit is intact.
For a professional finish don’t repair the power adapter cable – replace it. It looks better and takes less time therefore more cost effective. Only repair the adapter or jack if you are doing a job for friends or family BUT even then plan out your total cost compared to a replacement adapter as most adapter these days can bought for under £10 (about $15) whereas the replacement wire, jack and postage costs/travel costs to obtain the correct parts will most likely come near to this figure anyway.
A quick word about working SMART and not necessarily HARD
It is not cost effective for you to repair a motherboard component yourself. It takes years of training and practice as an electronic engineer with expensive equipment. If your customer insists on a repair then use another company who specialize in motherboard repairs for trade customers. Their usual price is around £99 so you should charge your customer accordingly for your time.
Overall it is more cost effective for you to replace the motherboard for them and this is the course of action we recommend.
How long this should take
Power problems can take anywhere between 5 minutes and a couple of hours to troubleshoot depending on what the fault is.