Original post by: Josh Aarons ,
I'm curious if you are getting any video output at all. If you boot the machine and hold down option, you should load the boot manager and at least get a black arrow. Dis-connect the hard drive, boot the machine and hold down option and lemme know what happens..also as a side note simple solution, take it to the apple store. Diagnosis is free, and I'm not sure the original drive in the machine had an operating system on it. If it's just a matter of installing the OS to a new drive, they should be more than willing. Again, for free.