does not power up

This usually means the the computer is unable to find bootable media. If you hold down the Option key (Alt Key) when switching on the Mac do you see any drives appear?

We can verify whether the drive is functioning correctly by following the steps below;

Start your Mac. Put your OS X install disk in the optical drive.

Restart the computer, then hold the C key during startup.

From the Utilities menu, choose Disk Utility. Don't click Continue.

Select your Mac OS X disk (named "Macintosh HD" by default) in the left side of the Disk Utility window.

Click the First Aid tab.

Click Repair Disk to verify and repair any issues with your Mac OS X startup disk.

After repairing the disk, try to start up normally.

If the repair fails then you will need to replace the drive. If this passes you will need to re-install your OSX from your provided installation disc.

Hope this helps,

Wes