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My laptop charger's transformer has a green light on it that indicates that it's plugged in and working.

When I plug it into the wall, the light goes on as expected. As soon as I plug it into the laptop, the light immediately turns off and my laptop doesn't get any charge.

After that, the charger's light doesn't turn green again, even though it is still plugged into an outlet. I need to unplug it from the wall and wait a few minutes. It's strange - unplugging and immediately re-plugging it does not bring back the charge; I have to wait.

Is this a charger issue or a laptop issue?

Edit: Hooked the charger into a voltmeter and power went through fine. I guess this means that it's a short in my laptop itself.

What are my options now?

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Yeah, most likely (though not certainly) something's wrong on the laptop side, possibly a battery with an internal short. Try running without the battery. –  Daniel R Hicks Apr 14 '12 at 9:41

4 Answers 4

This happens because of a short contact, which indeed is in either the power adapter or the laptop.

You'll first want to verify the charger, for which we will need a multimeter.

On the bottom of your charger you will find output information which we will need to match.

You need to put your multimeter on V- 20 and verify that it reaches the voltage, do the same with A- 10. In this case the results would be around 12 V and 1.0 A. If yours match then the charger should be fine.

Try to use your laptop without battery to see if it's the battery, else the power circuit of the laptop is broke. From this point on, it's a matter of going testing the connector and circuit to find the issue, or sent it back in if it's still under guarantee or you don't want to mess with it yourself. Good luck on finding a fix!

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My laptop still works fine on battery, though turning it off and taking out the battery, then plugging it in still shorts the charger the way I describe in the original question. Does that narrow the issue down at all? –  Corey May 17 '11 at 21:57
    
Have you tried the multimeter, if the charger voltage / ampere are correct your laptop's power circuit or power connector is short circuiting the power. –  Tom Wijsman May 17 '11 at 22:01
    
I hooked my charger into a voltmeter and power went through just fine. I suppose it's a problem with my laptop. What are my options? –  Corey May 17 '11 at 23:13
    
As said, either open up your laptop yourself or bring it to your local computer store (free if under guarantee, else it will cost you a bit). You would need to track down where the short circuit happens, thus whether it is in the connector piece or in the power circuit itself... –  Tom Wijsman May 17 '11 at 23:23
    
An ammeter (measuring current in a multimeter counts) is potentially dangerous for this situation.. they are essentially short circuits, and shorting any power line can cause rapid overheating. Depending on the charger, it can trip a temporary cutoff, blow a heat fuse (which is permanent, has happened to me before), trip the house/building's circuit breakers, maybe even cause a fire or melt something if those standard protection measures are not working. –  Bob Apr 14 '12 at 9:18

Try removing the battery. Plug in your charger to the socket and then the laptop, then slip the battery back in. It works for me.

Also, when the battery is full, plug in your charger while the laptop is off. This only works when your battery is at full power, so you should be switching off or hibernating your machine while plugged in and then disconnect the charger.

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Use a meter to check for proper output from the adapter. More than likely, its a short on the laptop motherboard. I ran into this issue with an old Dell d620, exact same problem. There was a short in the actual plug that was on the motherboard. Usually you can replace that if you are handy with a soldering iron...

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You're absolutely correct. I ran the charger through a meter and the power was fine, confirming that it is a problem with my laptop. –  Corey May 17 '11 at 23:14

It sounds like your laptop isn't charging at all. I'm guessing the laptop has no power, and is shut down. If not now, it'll be off soon enough...

Pull the battery out of the laptop, to see if the laptop will work (e.g. boot up) without the battery. If so, suspect the battery or the laptop's internal charging system.

Do you have access to another, known-good charger?
- If you have a multimeter, try probing the end that connects to your laptop. It can be hard to know what to expect the multimeter to read, without a known good charger to compare it to. - If your laptop is a common brand, you may be able to find another one at your school, your place of business, or "Free Geek" or perhaps even craigslist. - I'm guessing you don't want to buy a new charger just to test - perhaps your local computer seller (e.g. BestBuy, FutureShop, etc.) might allow you to test their units - they frequently sell "universal" chargers, which may work.

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protected by slhck Aug 28 '13 at 12:27

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