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.
June 19th, 2011 at 9:09 am
hey there
i have an acer aspire 5820t. it was working fine recently but stopped working a week ago. i have tried using the battery alone, no good, and the ac adapter alone, no good either. when i press the power button while using the battery or the adapter, the little blue light on the button blinks once and goes, same with the power light.
what could cause this problem?
thank you
June 16th, 2011 at 4:07 pm
Hi i have a Compact Presario f700, it was working three days ago but now for some reason it just stop working, when i press the power bottom, all the lights come on and five second later it turns off; it turns off so fast that my laptop screen doesn’t have time to turn on. also it seems that the fan tries to turn on but it quickly goes off. I don’t know what is happening. Please if you have any ideas off what could be wrong, i would be really thankful.
June 7th, 2011 at 8:33 am
Thanks for the information in the post… I have an HP Pavilion dv6500 series laptop. The laptop will not power on when plugged in with the adapter alone. If the battery is fully charged, the laptop will power on, but the AC adapter does not charge the battery. The blue LED lights up when AC adapter is plugged in… The power jack/harness measure 19.xx V across both wires AND to the MOBO (that is, where the plug connects to the jack soldered on the mobo.)
I do not see anything specifically spelled out that it is a fuse on the mobo.
Assuming that the MOBO is shot or shorting out somewhere… But just looking for a second opinion.
May 29th, 2011 at 1:34 pm
@ Mohsinreja,
Does it turn on at all? Does the power LED turns on when you push on the power button?
I would check laptop memory. Could be failed memory module.
May 20th, 2011 at 10:42 pm
i have HP Pavilion dv7-1240us laptop..since some days it is not power on..and no respons..i have allready change battery.but still same problem..please give me some solution with picture..i m waiting for your respons….
May 17th, 2011 at 1:49 pm
Joe,
It’s likely the power button itself is bad. I’ve seen it happening before with Satellite 1905 laptops.
I think you have a good chance to fix the laptop if you replace the power button board which located under the keyboard cover. It’s easy to replace this board. There is only one or two screws securing it.
May 17th, 2011 at 1:29 pm
laptop is a 1905 toshiba. power on button has gone from intermittent to worse. any easy repair here? everything works fine when the button finally turns on. nothing looks unusual when I popped the button cover off.
May 16th, 2011 at 9:12 pm
Melina,
Did you buy an original HP adapter or generic one?
I don’t really trust generic adapters.
I’ve seen a problem like yours before. One of my customer had a similar problem powering up his HP laptop with a generic adapter. The adapter itself tested fine but the power jack light wasn’t coming up. The problem was fixed as soon as I plugged an original HP adapter.
I cannot tell if replacing the AC adapter will fix your problem but in cases like that I always test laptops with original adapters.
It’s possible your AC adapter doesn’t work properly under load. This is just a guess and I could be wrong.
May 16th, 2011 at 3:55 pm
First of all, thanks for posting these DIY tips and tricks!
My problem…
I have an HP dv4-1147cl laptop (the bronze one)…with the symptoms as described on this posting. The power adapter that came with my laptop appears to have gone haywire. It was beeping and not charging the laptop…so I safely shut down the laptop and reordered a new power adapter, not thinking much of it. When I got the new power adapter I plugged it in to the wall and laptop and got nothing. No blue LED next to where you plug in the ac adapter to the dc in jack. The laptop is not powering up at all. Not even a blip of life. I tested the new power adapter with a multi-meter and it has power and is reading ok.
So, next I dissected the laptop to get to the motherboard and see if there was power to the dc harness. It appears that there is…but just to the red and black wires. Do you know if any of the other wires should have power?
Also, wondering if you know…does the motherboard on the dv4-1147cl have a fuse on it? I looked and looked…and just don’t see it. I had wondered if there is maybe a fuse built into the dc in jack instead??
I am really bummed, and not sure if I should order another dc jack and harness first…so if that works…and if not order a motherboard. I was really hoping there was some sort of fuse on the motherboard or maybe that dc jack…
Thanks…any help is greatly appreciated!!!
April 8th, 2011 at 12:52 pm
Kevin,
If the AC adapter rated 18.5V, it should output around 18.5V.
If your adapter outputs 15V, it’s not normal. Most likely it will not work when loaded (connected to the laptop).
Before you do anything else, test your laptop with a known good adapter.