My emachine wont boot up it has never booted it was sent to factory and returned still not booting

1. Boot the computer to the boot menu: To do this, restart the computer and press the appropriate key when prompted to enter the boot menu. On most eMachines computers, this is the "F12" key.
2. Select the CD/DVD drive as the boot device: Use the arrow keys to select the CD/DVD drive and press the "Enter" key to boot from it.
3. Insert the Windows ME boot disk: Insert the boot disk into the CD/DVD drive and restart the computer.
4. Choose the "Start Computer with CD-ROM support" option: When prompted, choose the "Start Computer with CD-ROM support" option.
5. Run the Windows ME setup program: The setup program should start automatically. Follow the on-screen instructions to install Windows ME.
6. Format the hard drive: During the setup process, you will be prompted to format the hard drive. Choose the "Full" format option to erase all existing data and perform a complete factory reset.
7. Install Windows ME: Continue to follow the on-screen instructions to complete the installation of Windows ME.

After the installation is complete, the computer should be in a factory reset state and you can begin setting it up as a new system.
Please note that resetting your computer to the factory settings will erase all personal data and installed programs, so be sure to back up any important data before proceeding with the reset.

I believe you might want to set the boot to

1 DVD (first)

2 SATA Drive (second) Maybe you didn't have this listed as 2nd.

If you have a disk in the DVD drive it will say press any key to boot from the DVD drive.

Check and see if there's a Disk in your CD/DVD ROM Drive. I assume there's on in there that has some bootable files and your computer see's it and is asking to boot from it. Usually it will say something like "Press any key to boot from CD" so if you don't want boot from that CD just don't press any keys.

If you can't get into the bios, you can't start a repair, when it's booting, continually press F2 to get the bios up, if that does nothing reboot an continualy press Del, this is for the bios menu and set the cd drive as first boot device.

If not continually press F8 on boot up this is safe mode, then when youre in highlight last known good configuration and press Enter.

Give this a try as your pc will not be set to boot from cdrom as default and will just try to boot into windows.

Seems a BOOT failure. Try eMachines Support: Support Documents

you will need to restart the computer and boot off the restore dvd.
This is done outside of the operating system.

When computer is first turned on keep hitting f10 untill you get the boot menu up, choose the dvd drive and it should work for you.

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

It sounds like you've had a fatal error - you can reboot the PC back to factory setting - this is called a hard reset - but before you do that - unplug you tower and clean it out (dust & dirt) - once you're done with that - restart you computer and press &hold down the "Ctrl" and "F11" button at the same time - this will let you reset the PC to the original factory configuration.

Are you attaching them properly
if so then it is something other then power supply
something has caused both power supplies to blow
have you installed anything in the first emachine you talk about

try this

http://support.microsoft.com/kb/294427

or this
http://support.microsoft.com/kb/867752/en-us