EMACHINE T1842 I TURN THE POWER ON THE GREEN LIGHT IS ON BUT THE COMPUTER WILL NOT START

do into the bios and ensure your plug and play is enabled..

I've had quite a few of these in my shop, and the problem is usually the power supply. Additionally, when the power supply goes out, it can do damage to the motherboard as well. First try swapping out the power supply and if that doesn't fix it, you will probably need a new motherboard.

Need more information but sounds like your optical drive may be failing or you have a software problem. Need more info please.

most likeley if you see something on the screen but it wont boot it is a mem problem, does it load bios, if so it is prob not memory

Follow these:

1. Unplug the computer.
2. Disconnect the power supply from the motherboard and all other accessories.
   
3. Replug the power supply.
4. Connect the green wire (PSON) of the power supply by way of a jumper wire to any black wire (ground).
5. The power supply should turn on with its fan. If not, it is defective and should be replaced.
   
6. Check the ATX12V connector of your motherboard. It is were you removed the 4-wire, 2 yellow and 2 black, connector of the power supply. Check the continuity of the yellow wires to the black ones. It should be open, otherwise it is shorted and your processor is defective and should be replaced.
   

Look in the manual there is a diagram and pin connections for each wire.

Take the battery out and unplug the power cord. Press down the power button continuously for a solid 30 seconds without stopping. This drains all the power out of the circuits and resets whatever invalid state your computer is in.

Now, leave the battery out but plug in the AC and turn on the laptop. If it works, turn it off again and insert the battery. All should be well.

Best way to check is to open your case. Near the power supply plug to the motherboard should be a little led light. If it is getting power to the board this light should be green. If it's unlit then most likely your power supply has gone bad. Hope this helps.

There are just too many eMachine models to be familiar with every one, however, as a preliminary inspection, remove the side panel, and turn the computer on to see if you see a green "Health" light. This will give you an initial clue as to how to pursue the problem. eMachines have historically had power supply problems. If you do not see a green health light on the motherboard, then your power supply is defective. A power supply supplies various voltages + - 5V, + - 12V ,etc. A power supply can be easily tested by a local shop with the proper test equipment. You might start there if you are a DIY! Short of that, you can purchase a power supply for under $65.00.

Motherboard failure, contact me for support, easy to replace
chris