Powermac G5 won't chime or display.

I originally had plans to do a hackintosh build since the mac was outdated to newer software. It originally worked 100% correctly given that there was a strange startup with that fans on full blast some times and then lowering after the OS successfully booted up. I took it apart to get measurements, later I thought better of cutting it up and reinstalled the powermac components. After installing everything i attempted to boot the system up. It seemed to boot up right for the fans, except the power LED would only turn on if you touched the power button and if you released it it would turn off. The mac would continue to run without the led on. There also wasn't a start up chime, nor a apple logo. And no there is no OS installed to the hard drive. Does the blank OS have anything to do with it?