I have a PMG4 that already has a 30GB drive in it with the OS on it and i added another drive to it and it will not recognize that drive. Any idea why it doesnt recognize it? I go to disc utility and it just shows the 30GB.
Did you configure the second drive as a slave (ie Correct Jumper settings - these matter on older IDE drives) , and checked the drive works in another machine?
Yup, same advice as above. You gotta configure the actual hardware jumpers on the drive correctly first.
You might also check the jumpers on the 30GB. Some drives have a "single" or "single master" setting, in addition to master/slave/cable select.