HomeLet’s say your laptop does not start at all. You plug in the power adapter and press on the power button, but the laptop will not react. It’s dead and the power or battery charge LED will not light up.
What could be wrong? Is it bad power jack or the motherboard is dead?
By the way, the power jack aka DC-IN jack is the power socket on the side or back of your laptop where you plug the AC/DC power adapter.
I’ll explain how to perform basic troubleshooting and find out what is wrong. This is only for experienced people, who know how to disassemble laptops.
First of all, test the AC/DC power adapter with a multimeter. It’s very likely that there is noting wrong with the laptop and your problem is related to the power adapter.
If the adapter tests fine and output correct voltage, disassemble the laptop and remove the top cover.
As you see on the first picture, in my laptop the power adapter plugs into the DC-IN power jack which is connected to the motherboard via a harness.
In some models the DC-IN power jack is soldered directly to the motherboard.
Plug in the power adapter and measure voltage at the point where the DC-IN jack or DC harness (like in my case) connected to the motherboard.
If you are reading the same voltage as on the AC adapter, it means the power jack or harness works properly and the problem is related to the motherboard.
If there is no voltage, most likely there is a problem with the jack or hardness and it has to be replaced.
By the way, in some case the problem could be related to the fuse which is usually located somewhere very close to the power jack/harness connector. You can test the fuse with a multimeter.
If the fuse is bad, the motherboard will appear to be dead even if there is nothing wrong with the power jack and AC/DC adapter. If that’s the case, replacing the bad fuse should fix the problem.
August 29th, 2010 at 10:36 am
Hi,
When I turn my laptop on the screen is black. The lights turn on (on the keyboard) and I hear the fan running, but my screen is still black. Recommendations?
Thank Yoyu
Christina
August 18th, 2010 at 3:39 pm
I have a strange problem recently with my hp laptop
although the battery is charged it doesn’t start when I try to start it with the battery only.
When I plug in the DC line it starts, I can even remove it after that and continue on using the battery.
any idea??
August 17th, 2010 at 9:33 pm
hi. i have a Hp Paviliion DV9000 laptop. i plug in the charger and the light shows blue, but it actually is not charging. i try to turn on the laptop and it would not turn on at all. at first i thought it could be the battery. so wht i did was use my friend’s laptop’s battery(shes got the same laptop) and the laptop turned on, the charger was plugged in but it was not charging. so at this point i dont know wht could be the problem. can u plz help me out here. thnx
August 14th, 2010 at 12:44 pm
Klasiq,
Maybe the DC jack harness is bad?
You can disassemble the laptop, plug the AC adapter and using a voltmeter test voltage on terminals where DC jack harness connected to the motherboard. If there is no voltage, the DC jack harness is bad and has to be replaced.
Take a look at these guide for some pictures: http://www.insidemylaptop.com/repair-damaged-power-jack-toshiba-satellite-l305-l355-laptops/
Again, find out if motherboard gets any voltage from AC adapter.
August 10th, 2010 at 6:04 am
i have this toshiba L305-S5919, (same as the pictures you have used to illustrate). the problem is the fuses are okey, no IC is Physically damaged (cracked, or visibly burned). the power adapter is okey, but when i the laptop is inserted nothing happens, all the power indicators are not showing. in short the laptop is dead, though when the power jack is inserted in the is power on the battery terminal meaning it should be charging but the indicators are not showing that anything. is there a way i can trouble shoot the board and get the problem.
August 4th, 2010 at 5:31 pm
Hi, sorry for my english.
I have an old Dell Inspiron. It doesnt start, no leds, no fan, nothing,
AC/DC adapter is fine. i don’t have the battery, anyway.
i disassembled my laptop, plugged in and tested the dc-in jack with a multimeter, and it reads around 7V, a lower voltage than measured on the AC/DC adapter conector (19,5).
Does it means dc-in jack is the problem?
Could it be the power button? Maybe is stupid but i don`t know if the measure is affected by the fact that laptop is turned off (although plugged )
Thank you
July 10th, 2010 at 11:42 pm
Ben,
First of all, make sure the laptop is assembled correctly. Check all connections, make sure CPU, RAM seated correctly, etc…
If everything looks normal, try turning on the laptop in minimum configuration: motherboard, CPU, memory, external monitor.
If the problem is still there, could be bad motherboard.
July 5th, 2010 at 4:29 pm
My laptop was not working because of a bad power jack. So, I took the laptop apart and semi-dissected the DC-IN jack. Well, I actually get the thing working but here is my new problem:
When I plug the power cord in, the laptop start’s up, by itself without me pressing the power button (it NEVER did that before). I see the fans starting up (the laptop is still opened up), I see the lights on the front of the laptop, and the disc drive, blink. Also, I will sometimes (i have tried starting up the laptop multiple times) hear a single electronically muffled beep sound from the speakers (the actual speakers aren’t causing this muffled sound). I do not see anything on the screen (in fact the laptop screen does not turn on at all). Any suggestion on what to do to fix this?
P.S. the laptop screen is NOT the problem
Thanks for the help,
Ben
June 28th, 2010 at 10:24 am
Leta,
If the AC adapter is OK and all connections are good, most likely this is the motherboard failure.
Here’s something to try.
Disconnect the AC adapter, remove the battery and wait for a few minutes. After that plug in the AC adapter and try turning it on.
If it doesn’t help, probably you have a bad motherboard (again, I assume the AC adapter is good).
You can remove the hard drive and install it into an external USB enclosure as explained here: http://www.laptoprepair101.com/laptop/2007/04/17/access-hard-drive-using-usb-enclosure/
Good luck!
June 26th, 2010 at 2:15 pm
Hi,
I have a Toshiba Satellite A105 (which I bought in June 2006), which shut down on me last a week ago. I had been working on it for about 10-15 minutes on a Word Document, when all of a sudden there was a “beep” sound and the screen went blank. There was no other sounds coming from the computer, no LED lights on (that show the battery charge, and such), and basically, everything looked completely dead. I had my AC adapter tested and it was fine, including the connection. I was not able to start my laptop since then.
Also, I don’t know if this has anything to do with it, but for the last month or so, my laptop had been using up it’s battery power very quickly (it was down from about 50 mintues to only about 15-20 minutes on a full charge).
Do you have any idea what might be wrong with it, and if it is fixable? And if it isn’t, how can I get most of my data off the hard drive?
Thanks!