iMac G5 - Must use open firmware to boot...

[DallasDeckard]

I have an iMac 20" G5 that used to be my kid's computer. I am trying to get it running smoothly to give to my brother for his children (my kids have a new iMac). This Mac had the power supply capacitor problem. I replaced all the bad caps and it started up fine for 6 months after that. When we gave the boys the new iMac for Christmas, I put this one in my Mac museum (turned off) resting comfortably. However, when I turned it on recently it kept getting stuck at the gray Apple screen. It wouldn't go past that, and the fans run at full force.

I started up in single user mode and ran fsck, there was nothing wrong with the disk. I tried to start up in Safe Mode, but it just hangs at the gray screen. Finally I booted into open firmware and entered "mac-boot" and the computer starts up fine. Once I do this, it runs fine, everything works, it is stable. However, I cannot start up unless I go through open firmware first.

Does anyone have any ideas why this is happening or how I can fix this problem? TIA....

Sean

 

[dtravis7]

Need to ask one question. It this an iMac G5 iSight by chance with the iSight camera or one of the older ones?

My iSight 20" did that and there were issues on the Logic board also with bad caps.

 

[DallasDeckard]

Need to ask one question. It this an iMac G5 iSight by chance with the iSight camera or one of the older ones?

My iSight 20" did that and there were issues on the Logic board also with bad caps.

No iSight camera. There were bad caps on the logic board as well? I fixed the ones in the power supply, but didn't know they were on the logic board as well. Ugh. I'll search the net for info about that, but if you have a site in mind that addresses this, please let me know. Thanks.