Replaced Logic Board and can't get to boot screen. Suggestions?
Ohhhkay. So, I replaced the PowerBook G4 Aluminum 15" 1.67 GHz logic board to resolve unusual screen pattern diagnosed as bad VRAM by TechTools.
Held my breath, plugged it in and restarted tapping the power button. I can hear the drive spin up and then down, I can hear the computer repeatedly accessing the empty CD drive. The caps lock light is operational, the sleep light is glowing steadily but the screen is dark and the computer doesn't boot. I can hear the computer repeatedly accessing the empty CD drive.
So I power down, then restart holding the power button down until I hear the fans blow hard followed by single tone, the sleep button flickers repeatedly for several seconds, then I can hear hard drive spin up, then down but the screen remains black and PowerBook tries to repeatedly boot from CD drive. Again.
So I put PowerBook G4 install disc in and PowerBook tries to repeatedly boot from CD drive, but still no boot up. And, of course, now I can't get the CD to eject. Other than the key caps light, the keyboard and track pad appear unresponsive.
Zapped PRAM, reset PMU, took it apart again, checked all logic board connections, but the same result.
Am I missing something?
Is this a good question?