iMac G5 shutting down by itself

[cielart]

My iMac G5 (second generation and, unfortunately, not under the current Apple fix) is shutting itself down. The log states that the shutdown cause is -122 and it happens after an FWOHCI Error trying to clear PHY ports. My hardware overview lists no volume or speed for my firewire. Neither firewire port will work when I tried them with my printer. I reset the SMU last night and my hardware overview actually showed a firewire speed, but this morning the G5 had shut down again and the firewire info was gone. Another odd bit of info, around the time this started happening, the date was listed as Jan. 11, 2023. Any suggestions?

 

[kbear]

Date problems usually indicate a need for a new PRAM battery and/or a PRAM or PMU reset. It can also cause it to shutdown in some cases.

Here's how to replace it:
http://docs.info.apple.com/article.html?artnum=300205


Here is Apple's doc for resetting the PRAM and PMU:
http://docs.info.apple.com/article.html?artnum=301733

However it may be that the FW ports are truly bad signaling a need for a logic board replacement.

I see you use the FW for your printer otherwise you could just disable the system's interaction with the ports.

See this:

http://discussions.apple.com/thread.jspa?messageID=4020216

 

[nixgeek]

Take it to an Apple Store anyway. Mine is a 2nd gen iMac G5 as well and after I printed out some information I found on the Internet as well as the Apple page describing the Repair Extension program, they replaced my parts for free even though my serial number was not in the range. Make your preparations and take your iMac to the Apple Store or an Apple Authorized Service Center. If you're still within the three-year period from time of purchase, you can still get the parts replaced.

 

[cielart]

Take it to an Apple Store anyway. Mine is a 2nd gen iMac G5 as well and after I printed out some information I found on the Internet as well as the Apple page describing the Repair Extension program, they replaced my parts for free even though my serial number was not in the range. Make your preparations and take your iMac to the Apple Store or an Apple Authorized Service Center. If you're still within the three-year period from time of purchase, you can still get the parts replaced.

Thanks so much. What info did you print from the internet?

 

[nixgeek]

http://www.popularmechanics.com/technology/upgrade/1707756.html

http://discussions.apple.com/thread.jspa?messageID=6401119

http://docs.info.apple.com/article.html?artnum=302181

If you can, open up the back of it (there are three screws on the bottom of the screen) and look for bulging capacitors or any that have leaked in the areas shown on the Popular Mechanics article. Mine had the caps sorted in a different fashion as that in the picture (the one in the picture is a first-gen model), but the afflicted caps were in the same vicinity as the one in the picture.

 

[macworks]

Bad power supplies are common in iMac G5 machines. Sometimes the logic board is bad too, but I've personally seen many more bad power supplies.

 

[nixgeek]

Bad power supplies are common in iMac G5 machines. Sometimes the logic board is bad too, but I've personally seen many more bad power supplies.

Well, on mine they replaced both the PSU and the logic board. Mine had some really bad caps. Not sure about the PSU though. Still, any of them might have been the culprit.