View Full Version : Dual 1.8Ghz G5 - Dead Processor B?

Feb 14, 2010, 08:56 PM
Hoping some people might be able to shed some light on on an issue I'm having.

I have a g5, dual 1.8's - and last night the computer started acting flaky all of a sudden. I go to check temps and low and behold there is only one processor showing up. So I run a backup and turn off the machine. I came back home tonight from work and it wouldn't even start.

I opened it up, dusted it out real well, then tried again. Same thing happened, although I noticed it seemed to start up, just with bad video. The card was a 256mb ati card, and I then proceeded to replace it with the 64mb card I got with the machine. Powered it up, booted right up, and wow it showed both cpus!

About 10 minutes later it froze. Powered down, then back on a bit later. Booted up but is showing 1 cpu again.

Anyone have any idea what is going on? Is the cpu dead? Possibly a heatsink or thermal compound problem? The fact that it saw the cpu for a second time makes me think the cpu isn't exactly dead. Like I said, dual 1.8's 4GB ram, two hard drives.

Any help would be greatly appreciated. Thanks and take care.


I'm open to all suggestions, though buying a new machine is out of the question for me at the moment, even if they are only $300-400. I'm pretty much working a dead end job and going to school full time so money is a bit tight. (computer graphics tech. student so this computer is important to me) I do have access to two more g5 cpus though. 1.8ghz, not sure what version. The computer seems to run stable on one processor at the moment. I'm not going to be doing much strenuous activity on it for the time being.

Feb 15, 2010, 05:57 AM
It could be dead CPU or logic board. If you have another 1.8 CPU (as you wrote), check it's serial number first. To work with your current (good) CPU, it should be pulled out from 1.8 DP. CPU from single version will not work AFAIK.
After CPU replacing you must run Thermal Calibration (if not, fans will be run on full speed and logic board will get wrong temperature readout form CPU).

Feb 15, 2010, 11:19 AM
Roger that, thanks for the response. Don't know if I'm actually going to try this or just sell it in hopes to save for another machine. Not exactly sure what the thermal calibration is, but will definitely look into it.

Feb 16, 2010, 03:58 PM
If you're SURE it's the B processor, install the Developer's Tools and install the Processor Palette into System Prefs. Click it and turn off the second processor and see if you're still having problems.

EDIT: You want to be sure it's the B as I believe you cannot shut off the A processor.