Let’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.
Home
September 10th, 2009 at 9:14 pm
АК,
It’s possible that your laptop doesn’t start because one of the memory modules is bad.
You have two memory modules installed, correct? Try removing them one by one and test the laptop with each module separately. If one of the memory modules is bad, the laptop should start with video when only a good module is installed.
September 10th, 2009 at 9:04 pm
AK,
You’ll have to disassemble the display panel and take a look at the video cable. If it’s made by CMI, I would definitely try replacing the cable first.
September 9th, 2009 at 8:12 pm
Hi folks,
I am having a Toshiba Satellite M305D-S4829, with Vista 64-bit. When I switch on the power on button, NOTHING happens. There is no display. I inserted the Recovery DVD to re-install Vista, and I could hear the DVD being ‘read’ by the laptop, but nothing happens. Tried pressing and holding “C”; tried FN key + F5, as well as F12.
I need help a.s.a.p.
Any input is helpful, as long as it does not involve using multimeters and tinkering with the motherboard.
Thanks,
AK.
July 28th, 2009 at 11:18 am
Hi,
I have a sony TZ150N dropped on the floor which does not power on anymore. Either on battery or power cord it blinks the power led once and nothing happens. I was thinking to buy a new motherboard but what if that is not the problem. Any ideas? I have unplugged all cables from M/B except power button cables and power jack. Same…power led blinks once. Is that the ultimatum test to see if M/B is dead? Should at least the led stay ON if M/B was ok?
Thanks.
July 12th, 2009 at 8:34 am
i have no power when i try to start my gateway laptop.
at first, it would power up and then immediately power down.
now, i have nothing power light doesn’t light at all.
July 6th, 2009 at 10:49 pm
Sia,
Bad hard drive? Can you remove the hard drive and start the laptop without it?
Find out if video will stay on the screen when the hard drive is removed.
July 4th, 2009 at 7:19 am
I have a Sony laptop FXA63. When turned on, the screen shows “Sony” logo and then a short blinking “-” at top of the screen and then nothing, screen dark. I opened it and noticed that fan comes on for and then stops, and the housing containing the fan heats up tremendously with fan not working. Can you advise on what to test next? Thanks.
June 29th, 2009 at 3:23 pm
Jawed,
If the laptop is absolutely dead even when you use a know good power adapter, most likely you have a problem with the motherboard.
Does the power LED flicker if you wiggle the power adapter plug inside the power socket? If it does, there could be a problem with the power jack. If not, most likely it’s bad motherboard.
June 29th, 2009 at 3:14 pm
mimmer,
The power board and power button board are two different things. I think in the comment 24 you asked about the power button board but called it power board.
I think you have a problem with the motherboard.
June 27th, 2009 at 7:28 pm
Laptop Tech, Hi,
it has a separate power button board and the quick buttons for email,internet etc. are also on that board