Apologizes your question hasn't received a solution until now. I have been 'away from my desk' for a while.
The eMachines T2240 desktop pc uses an Intel D845GVSR motherboard.
So let's go to Intel Support for more information, and to the specific product download page for the Intel D845GVSR motherboard,
Intel Desktop Board D845GVSR Product Guides
On this page left-click right on the blue title -
Intel Desktop Board D845GVSR Product Guide (PDF)
This is a PDF file. The computer you are using has Adobe Reader on it which uses PDF files.
After you have downloaded the PDF file go to the top left and hover your mouse cursor on the rectangular icon. (To the left of the Up/Down arrows and Page: )
Hovering your mouse cursor over this icon will briefly reveal -
Toggle Sidebar. Click on this icon.
Now click on the icon to the immediate right of it. (Show Document Outline)
Scroll the Show Document Outline sidebar down until you see the heading - Connecting Internal Headers -
Now click on the heading immediately underneath it -
Connecting the- Front Panel Header -
[The front of your computer is the Front Panel. The area of connecting pins on the motherboard for the Front Panel is the Front Panel Header ]
On Page 11 in the Product Guide we see that S designates the Front Panel Header.
On Page 31 in the Product Guide it shows the Front Panel Header pinout. (The Front Panel Header is designated by C in the illustration)
Again on Page 32, it shows where the Front Panel cables connect to.
In case you are not able to view the Product Guide;
Viewing the motherboard installed in the computer case, the Front Panel Header lays parallel to the bottom of the motherboard, at the Bottom Right.
It is rectangular in shape and has 9 pins.
4 pins along the Top, and 5 pins along the Bottom.
The pins are numbered Even along the Top row;
Starting from the Left side of the Front Panel Header going to the right;
Pins 2, 4, 6,and 8. There is NO Pin 10.
The pins are numbered Odd along the Bottom row;
Starting from the Left going to the right;
Pins 1, 3, 5, 7, and 9.
A) Pins 1 and 3 are for the Harddrive Activity LED.
Pin 1 is for the Positive ( + ) wire. Pin 3 for the Ground wire.
In case the HDD LED is dim when the HarDDrive is active, switch the wires around. (Computer off and Anti-Static Precautions used)
B) Pins 5 and 7 are for the Reset switch, IF a Reset switch is used.
Pin 5 is for the Ground wire.
C) Pin 9 is for 5 volt ( + ) power. Not Used.
(Usually the motherboard manufacturer uses this pin to test the motherboard)
D) Pins 2 and 4 are for the Power On LED.
-> Believe Pin 2 is for the Positive ( + ) wire.
If PWR LED is dim when computer is on, switch the wires around.
E) Pins 6 and 8 are for the Power On switch.
There is No Pin 10.
For additional questions please post in a Comment.