How to Troubleshoot a Laptop Screen That Shuts Down

For this issue, you may take it to repair or replace your laptop dc jack. If you are good at tech, you may fix it by yourself on the basis of the following instructions:
http://www.chargerbuy.com/blog/dc-power-jack-repair-guide-do-it-yourself-instructions/

Could be a combination of things.

1) Battery is low. Not enough power to turn the laptop on.
Caused by;

2) AC adapter has a plug on the end of the cable. The plug plugs into a DC Power Jack on the laptop.

The DC Power Jack is bad.

2a) The DC Power Jack has a bad connection to the motherboard, (Cracked solder joints), and/or the jack itself is bad.

2b) Center Pin is loose in the jack's mount.
The back of the Center Pin where it mounts has become loose.

2c) The plastic body of the jack, which composes the jack's case, is cracked. This allows movement of the Center Pin.

2b, and 2c cause a bad connection with the AC adapter plug.

No charge to the Battery, no power to the laptop.

http://www.laptopjacks.com/view_part/For-Gateway-MX6920-DC-Power-Jack-GW51425.html

[ If this is the case the DC Power Jack needs to be resoldered to the motherboard. The cracked solder joints need to be re-melted, (Reflowed)
Entire laptop needs to be disassembled down to the bare motherboard in your hand.
(No Processor, Ram Memory, or any adapter cards mounted to the motherboard. Nada)

OR,
The DC Power jack needs to be replaced.
This entails disassembling the entire laptop, down to just the motherboard in your hand. (Same as above)

The old DC Power Jack is de-soldered, and a new one soldered in place.

Very FEW computer repair shops have the necessary skill level.
They just want to replace the entire motherboard.
IF one is available.
More Ka-Ching for them also. ]

3) The AC adapter is bad.
Not providing power to the laptop, to charge the Battery, nor give power to the laptop without the Battery.

AC adapter cord from adapter to plug, which plugs into the laptop, (DC Power Jack), may have a break in it.

May be an intermittent contact provided by wiggling the cord.
If this is the case the wires have stretched, and broken.
Wiggling causes the wires to briefly touch, and make contact.

Where this cord meets the plug itself. A lot of times there is a break in the wires in this area.

Solution is to replace the AC adapter. There are universal AC adapters you can buy, or perhaps Gateway still has some for sale.
(Ka-Ching)

1. Take the battery out of the laptop & try to turn on the laptop using power adapter only. If the computer turns on, then the battery is defective & needs to be replaced.
2. Make sure the power adapter is not defective. Test the output voltage of the power adapter using a voltmeter. Compare the voltmeter reading to the nominal value written on the adapter or the laptop.
3. Make sure the DC jack is not loose or broken. A loose DC jack will need to be re-soldered. A broken one will need to be replaced.
4. If you have another processor which is compatible with your laptop's model, try swapping processors & test to see if the laptop will work.
5. The power button could be bad.
6. The motherboard could be defective & needs to be replaced

You First need to test your AC Adapter Cord...
You can test if you have a secondary known working one.. plug that one in to see if same issue occurs.. OR you will need to test the AC Adapter using a multimeter (available at any home improvement store for under $7).. When testing the Plug End on the AC Adapter - Hold The Negative Test Prod Of the Multimeter to the Outer Side Of the Plug Tip, and Put The Positive(red) Test Prod Inside The Plug Tip... See If You Have Power Through The AC Adapter Tip... You Might Need To Slightly Wiggle The Cord Near The Tip End To See If THere Is A Short In The Cord....

If Cord Tests Good....

You Will Need To Replace The Laptops DC Jack...
The DC Jack is the port where your AC Adapter Plugs into on the laptop..

Your Faulty DC Jack Would Need to be desoldered, the motherboard cleaned of all old flux, Re-Tin The Contact Pads and then Resolder a New DC Jack Onto The Motherboard...

It may be that you need a new, (Or good condition used), motherboard. You may not.

The problem could be the DC Power Jack. The DC Power Jack is small, and the body is made of plastic. Sometimes there is a metal shell around the plastic body. (The jack is a rectangular shape, and is just a little larger, than the outside portion of that AC adapter plug!)

This is an example of a DC Power jack for a Toshiba Satellite a215-s5807,
http://www.notebookworks.net/ProductDetails.asp?ProductCode=NBW52-0133

As you know there is a metal pin in the center, and at the back of the round hole, there are flat metal contacts.

Let me explain the construction of a DC Power Jack, and how it's mounted to a motherboard. This all has relevance to the solution.

Your laptop uses DC electricity. (The AC adapter converts AC to DC. Your laptop battery, and a flashlight battery, are examples of stored DC electricity)

DC uses a Positive connection, and a Negative connection. The metal pin in the center is Positive. The flat metal strips at the back are Negative.

That laptop DC Power Jack has metal prongs, that come out of the plastic body. One prong, (Or pin), connects to the Positive metal round pin, in the center of the jack.
There may be one, or two prongs, (Or pins), that come out of the plastic body, and connect to the Negative side of the jack. (Flat metal strips)
These prongs go down through holes in the motherboard, and are soldered on.

With the AC adapter plugged in, an accidental bump on the plug itself, could break the body of the jack, or break solder joints that hold the jack to the motherboard.

AC adapter removed, and battery removed. Use a NON-metallic object, and see if you can make the center pin of the jack move. See if the entire jack itself seems to move.
A.If the center pin moves, you have a broken DC Power Jack.
B.If the entire jack moves, you have cracked solder joints. (Broken)

Replacement of the DC Power Jack for A.
Re-solder the solder joint/s for B.

Cost of replacing a jack at a reputable computer repair shop? $90 to $150
Cost of re-soldering solder joints? $50 to $90
Cost of replacing the motherboard?
$250 on up.

If you are a skilled person with the correct tools, it is feasible for you to replace the jack, or re-solder the solder joints.
It is also feasible that you yourself, could replace the motherboard.

Some laptops have a poor motherboard design, for where the DC Power Jack is mounted to the motherboard.

Crude explanation would be, that the main body of the motherboard is a 1 foot square. Then a 2 inch square comes out of the side of the main body.
The DC Power Jack is mounted to that 2 inch square. From accidental bumping, OR just normal usage of inserting, and removing the AC adapter plug, this 2 inch square can crack away from the main body.
This, of course would require a motherboard replacement.

Disassembly instructions for a Satellite A200 and A205 Series laptops. Very close to the A215 Series,
http://www.irisvista.com/tech/laptops/toshiba-satellite-a205/laptop-disassembly-1.htm

(Don't forget to buy, and use a cheap ESD wrist strap, to prevent static shock to the delicate hardware components, inside your laptop. Average cost is $7)