Power cord cuts in and out

You can start by checking that charge cord has power out to lap top with a multi meater or voltage indicator if there is then it is ither the l.e.d. is burned out or if there is power all the way to the baterey then mostlikely a battery has built up a "memory" when we recharge a battery that has not been discharged properly it builds a "memory" and will only take a partial charge

Measure the voltage at the terminals of the battery in the laptop. If there is no supply then the power section in the lap tops main board is faulty and needs a check.
However if there is voltage then the battery must be checked if this has failed to charge and is defective. check if the cord from the adapter is not short as it will result in DC power cut off.

push f2 four times then put your computer on f12 command then run windows on D:drive.

start the machine up with the power cord in it, and after it starts remove the battery, the pc should stay on, and be usable. if not then the port is bad. if it does, then its the battery that will not charge.

it needs a new a\c power block inside they are cheap and semi difficult to repair i wouldnt think it would be over 100$ max but it isnt in my lap to inspect so this is my opinion ok

Does the cable seems cut near the jacks? Try with two car lamps connected in series (12v each) to see if the power supply works OK.

Stelios.

My Dell laptop has a power problem.

The Dell Precision M20 Battery stops charging when I move the power cord on the DC adapter. When I start moving the cord left to right, the power LED light on the front goes on and off and the battery charge LED goes on and off too.

I removed the precision m20 battery and tested the laptop again. The laptop starts fine from the DC adapter when the battery is removed, but as soon as I start moving the power cord the laptop shuts off. It looks like the laptop looses power immediately.
If you have a problem like that, most likely it’s related either to the power adapter or the DC-IN power jack.
First of all, I tested the laptop power ac adapter with a multimeter. The power didn’t cut off no matter how badly I moved the cord. The power adapter output voltage was 15.45VDC all the time. That means there is nothing wrong with the power adapter and most likely there is a problem with with the power socket inside the laptop.
Now I’m going to test the power socket inside the laptop.
In order to access the power socket I had to disassemble the laptop and remove the top cover assembly with the display.
You can find disassembly instructions for many HP, Dell, IBM, Lenovo, Sony and Toshiba laptops in these service manuals and guides.
In the laptop I was fixing (Tecra M2) the power jack is attached to a DC-IN harness and this harness can be unplugged from the motherboard.
As you see, I removed the DC-IN harness from the motherboard, plugged in the power adapter and tested continuity with my multimeter as it shown on the picture.
When the power cord is still, the voltage output is 15.45VDC, the same as on the plug.
But as soon as I start wiggling the plug inside the jack, the power cuts off and voltage goes to 0. It means, the power harness is bad.
The problem was fixed after I replaced the defective DC-IN harness with a new one.
In some laptops the power socket (DC jack) is soldered to the motherboard.
If the battery stops charging when you wiggle the power plug inside the jack, either you have a bad power adapter (test it with a voltmeter) or the power jack is broken or loose.
You cannot simply unplug the jack and replace it with another one. You’ll have to unsolder the old jack and solder a new one back on the motherboard as I described in this post.
If the power jack is not broken but loose (not making good contact with the motherboard) you can resolder the old jack without replacing it with a new one.
If you want to buy a new one,you can see more information from http://www.udtek.com

check for shorts in the power cable or loose or broken power jack in laptop

This problem is either due to your power adapter, wall plug or the back of your lap top where the power adapter goes into. My guess would be the power adapter, they are infamous for going bad. Try wiggling the cord that connects to the power brick (black box) from your lap top.

It could be one of three things. It could be a bad battery, a bad ac adapter, or the recharging circuitry could be bad. I would try pulling the battery out, and see if the laptop will startup and run strictly off of the ac adapter. If that does not work, you have a bad ac adapter. If that works, and the battery has any charge left, try running it strictly on the battery. If it doesnt work, you have a bad battery. If it does work, the circuitry is bad and you will probably need new motherboard. One other thing you can check is where the ac adapter and battery plug into the laptop, and make sure there is no corrosion that could be causing a short.