Power Connector
A common weak spot on most laptops is the DC power jack. If someone trips on the wire while you have the power adaptor plugged into your laptop, chances are that the power jack will get damaged.
On most laptops the DC power jack is soldered directly to the motherboard and there are only three or four small pins holding it in place. Unfortunately that makes the power jack quite weak. Any sideways pulling of the DC power cord while attached to the laptop will usually dislodge at least one of these pins, breaking the solder around it. Modern laptops use quite a lot of power, from about 70W to 120W or even more. The bad electrical connection from the dislodged pin will cause sparks and heating that will eventually burn a hole through the motherboard and can even be a fire hazard. The usual signs of that are:
- The battery is not charging properly or stays at half charge despite that you have been using the power adaptor.
- The screen flickers (the brightness is changing) while the power cord is plugged in. This is caused by the laptop switching between DC power (screen is brighter) and battery power (screen is dimmer).
- The DC plug gets hot after a few minutes of use and may even smell of burning.
- There are “scratching” sounds coming from the DC jack.
All of these symptoms are caused by poor contact between the DC power jack and the motherboard.
There are several models of laptops that are resistant to this problem. All older Dell laptops that use the three pin DC power jack are usually not affected, probably because the power cord pops out easier. Also some older Sony Vaio models, and 1-2 Toshiba models where the DC jack is attached to the case away from the motherboard and all new Apple laptops, where the DC power cord is magnetically attached to prevent any damage to the laptop if someone trips on it.
To test for broken power jack:
- Remove the battery
- Plug in the power cord
- Start the laptop
- Gently wiggle the DC power plug on the back of the laptop
If your laptop shuts down abruptly (looses power), find a repair shop that can resolder or change the DC power jack as soon as possible, as the motherboard has already started to burn around the dislodged pins. Some repair shops will offer to replace the whole motherboard, however the price of a new motherboard together with the labour charge for installing it will usually be greater than the current value of your laptop and can go well over a thousand dollars.
Replacing or re-soldering the DC power jack is not an easy job too. It usually takes two to three hours depending on the damage and the model of the laptop. To reach the power jack, the laptop has to be completely disassembled and the motherboard taken out. Then if the board around the dislodged pin is badly burned, the power jack has to be un-soldered and the board has to be patched. After that a different power jack has to be installed, attached to the case of the laptop and connected with wires to the motherboard, as the patched board wouldn’t be strong enough to support the original type of power jack that was soldered directly to the board.
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I accidently plugged my external hd power adapter in to my laptop’s ps/2 mouse port. Now the only way I can power my laptop is with both the external drive power adapter and the laptop power adapter. Any ideas?
Is anyone aware of commercially available DC power cables that can connect directly to the connector that the battery normally connects to, thereby not requiring repair of the non fuctional DC jack ?
Thanks the note above helped me so much, keep up the good work
The power cable indicator shows it working find, but then it started showing not charging on the laptop I wiggle it and it works and then one day as plugged the cable into the laptop, I smell a burnt and a smoke at the back of the laptop where plugged the cable since the laptop want power up. please tell me what the problem could be and what to do to solve it
Well i had similar problem, whit an old hp-compaq nx9010 motherboard dc connector jack, whit a de-soldered in few junctions , i open it removed the jack, clean the board whit 66% anti-septic alcool, “rash” a bit the conection point to gain few “grip” to the new soldering material, fixed a bit the oldjack whit melted plastic that i did whit soldering-iron,puted back the jack on place,worked whit cold iron material and after i heated up , wen i started the laptop hp-compaq nx9010 it was like new!!
Just to prevent that the jack would givehim selft a lack ,i have filled the sides and top so the case could make pressour on the jack.
Also adapted 2 wireless antenas in lcd frame and a wireless adapter,trade also a new 15″ lcd screen from a dell p-70 or so,all worked just fine.
Now my problem is to adapt a acer 1690 14.8V/4.400Mhl, to the hp-compaq nx9010 laptopseries that also uses a 14.8V/4.400Mhl batery…..i have the datasheet for the acer battery, description for each pin, now im having dificulty to find the hp-compaq nx9010 motherboard pinout description…
can any one help on this one since this guy HAS A GREAT WEBSITE IN THIS AREA!
Can anyone tell me what is the purpose of the boot on a dc powerjack harness? I’m replacing a harness on a toshiba laptop, but with the new harness, the boot is at the jack side, and it was on the motherboard side on the old harness. The boot makes it impossible for me to put the top cover back on my laptop. I see that under the boot is a plastic piece with the wires wrapped around it a time or two. What does that piece do? If I removed that piece, would that damage my laptop? It makes me think that it has something to do with regulating the power going into the motherboard? I have seen pictures of other harnesses, and with some models of laptops, they don’t have the boot. Any help? Thanks, Ron.
Hi !
From a friend I got a laptop HP nx7400. He told me it suddenly lost the power and that it just would not power up again. He was mentioning some possible lightning strike but the charger that he was using at that moment is still ok and working.
The day I got this laptop I tried to switch it on and nothing happened. I check on internet about what could be wrong and found a post about ‘power reset’ which says: remove the battery, unplug the power and then press the power button on the laptop for some 60 seconds. Then you plug in the power and press the power button and it should start. I tried it but no success.
I left the laptop with the battery out for some 3 or 4 weeks and then decided to repeat that ‘power reset’ again. This time it worked and the laptop started and I was able to work normally for few hours. After I switched it off and then tried to use it again next day there was the same story – it wouldn’t start up, no power. I tried the ‘power reset’ few times but no success.
Again I left the laptop for some 3 weeks and before I plugged in the power, I did the 60 second power button press and after plugging in the power it started. This time it worked maybe some 5 minutes and then the power went off and immediately on again and it worked for few minutes again (less than the first time) and another power reset and this was repeating few times and the times while it was working got shorter until it wouldn’t power up again.
Actually the same situation repeated for the second time. Leaving it for 3 weeks I was able to start it up, but it would start ‘restarting’ and the time being powered on got shorter and shorter until it would not power up again.
Does anybody has any idea what could be wrong and how to fix this situation.
Thanks in advance for any help,
Regards Milan
the same problem you have explained here I have nothing new except the model mine is 4500 just started yesterday,I broke the dc jack and replaced it ages before about 5 months worked perfect but now has started again I WILL TRY TO RE SOLDIER IF NOT FIX THE PROBLEM I WILL BUY NEW DC-POWER JACK,BUT MY ISSUE IS LAST TIME I REPLACE THE JACK IT DID COME OUT WITH 2 TRANSISTORS BUT STILL WORKS UNTIL YESTERDAY START OVERHEAT DO YOU THINK IT IS BECAUSE OF THAT AND WHY YESTERDAY WHILE I HAD IT 5 MONTHS AND NO PROBLEM? BECAUSE MY DC IS REAL INTACT I HAVE CHECKED IT IN THE MORNING TOO
I have an asus g50vt laptop, smoke came out from power jack. Now when I plug power adaptor it shorts
laptop still works with battery. I removed mother board to see if it can be fixed it’s pretty well fried.
I know they make external battery chargers but is there another way to power laptop via docking station or other method. I do not want to replace mother board because I understand this is a comon problem on this model. it was about year and a half after new purchase, contacted asus out of warranty.
Any advice would be appreciated thanks!