The eMachines T5274 uses an ECS 945GCT-M3 motherboard.
This is ECS Support, and the download page for the motherboard manual,http://www.ecs.com.tw/ECSWebSite/Product/Product_Detail.aspx?DetailID=719&CategoryID=1&MenuID=16&LanID=0
To the right of the Download Site heading, (At the bottom), left-click on the country nearest yours.
This is a PDF file download. Takes a few seconds to see the first page come up, and additional time for the file to fully download.
After the file has fully downloaded, go to Page 11.
(The PDF file page number box at the top, next to the blue Down Arrow, will show 11)
In the motherboard photo shown, the number 12 points to Panel1.
This is the Front Panel header.
(The Front Panel is the plastic front of your computer. This particular connector is referred to as a Header)
Barring you cannot download the motherboard manual, I will explain in detail as I go along.
Orient the motherboard in your mind, so that we are both looking at it in the same direction.
Processor to the top, Ram Memory slots to the right, Panel1, (Front Panel header), is at the bottom Right corner, and is along the edge of the motherboard.
There are 2 rows of pins. One row along the top, one row along the bottom.
4 pins along the top, 5 pins along the bottom.
The Bottom row of pins are numbered Odd.
The numbering starts from the Left side of the motherboard, and goes towards the Right.
The Top row of pins are numbered Evenly.
Numbering starts from the Left side of the motherboard, and goes towards the Right.
Top row numbering of pins, starting from the Left side, going towards the Right,
2, 4, 6, 8, and 10. There is No pin 10. Just a flat spot.
Bottom row numbering of pins, starting from the Left side, going towards the Right,
1, 3, 5, 7, and 9
A) Pins 1 and 3 are for the HarDDrive activity LED light.
Hard Disk LED (+) The Positive wire of the HDD LED light goes to Pin 1.
The Negative wire of the HDD LED light goes to Pin 3.
More than likely if the wires are marked, only the Positive ( + ) wire will be marked. Usually with a little tag that has + symbol on it.
B) Pins 5 and 7 are for the Reset switch.
IF, a reset switch is offered on your eMachines.
Pin 7 is for the Positive wire. (+)
(It isn't necessary to have a Reset switch. It's a restart switch. Used to restart your computer, and there are many other options available)
C) Pin 9 is reserved, and not used.
D) Pins 2 and 4 are for the Power On LED light.
Pin 2 is for the Positive wire. (+)
(If the two wires are reversed, the Power On LED light will be dim)
E) Pins 6 and 8 are for the Power On switch.
Pin 6 is for the Positive wire (+)
Have any questions regarding this, post in a Comment.