Can't Shut Down

[DVDSP]

Last week we lost power and for some reason my Dual 450 started up on it's own (it's on a UPS). Ever since then I haven't been able to shut it down. Whenever I choose "Shut Down" from the Apple menu I get the "Cancel/Shutdown" prompt, click "Shut Down" and it goes through the regular shut down cycle. Then, as soon as the light in the power button goes off, it automatically starts back up.

I've zapped the PRAM and checked the system pref to make sure the box for auto restart at power failure is off (it always has been, by the way). Can't figure this out.

Running OS 10.2.5.

Any suggestions?

 

[applemacdude]

Open the mac and press the CUDA button once without the the plug on, Once with it on and once while its running up.

 

[shadowfax]

what does CUDA stand for?

 

[andyduncan]

Originally posted by applemacdude
Open the mac and press the CUDA button once without the the plug on, Once with it on and once while its running up.

Pressing CUDA while it's on or starting up? I thought that was a no-no. Besides, that would be a pretty tricky thing to do since you'd have to trick the mac into thinking it's case was closed.

AFAIK the correct CUDA/Power Manager reset procedure is to yank the power cord, open the case, press and hold the CUDA reset button for at least 10 seconds, and then start the machine up.

edit: clarified instructions

 

[MacBandit]

Do you have powermanagement software with the UPS? If not have you checked the options under the energy control pane in system preferences. There's an option there for restarting automatically after a power failure. Maybe somehow the software has gotten screwed up and on shutdown it just restarts now.

 

[applemacdude]

Originally posted by andyduncan
Pressing CUDA while it's on or starting up? I thought that was a no-no. Besides, that would be a pretty tricky thing to do since you'd have to trick the mac into thinking it's case was closed.

AFAIK the correct CUDA/Power Manager reset procedure is to yank the power cord, open the case, press and hold the CUDA reset button for at least 10 seconds, and then start the machine up.

edit: clarified instructions

Pressing the CUDA button while it's on is like pressing the button 100 times (or so ive heard), It actually works, all it does is restart the computer...Ive havnt heard of any mac get "hurt" doing this precedure...( Anything that happens isnt my fault)

 

[DVDSP]

Thanks for the input

I reset the CUDA but it apparently didn't do anything to help the situation. The only way I can Shut Down is to push and hold the power button. However, when I do that it won't restart UNLESS I shut off the UPS. Then, when I turn the UPS back on the Mac starts up immediately without me pushing the power button.

Any other suggestions?

PS: to clarify, my Energy Saver System Pref is NOT set to "Restart automatically after power failure."

 

[Veldek]

I have a very similar problem. I wrote this before but the post wasn't accepted by the server, so I try again but shorter:

My iMac's battery is low, because I had it plugged in a switchable outlet. I took it out but left all devices there. Now when I try to shut down, it will restart, if I turned off the outlet. Only if I leave it on until the iMac is shut down, it will work.

I zapped the PRAM, but that did not help. So if these problems have the same reason, perhaps someone here knows it?

 

[MacBandit]

Re: Thanks for the input

Originally posted by DVDSP
I reset the CUDA but it apparently didn't do anything to help the situation. The only way I can Shut Down is to push and hold the power button. However, when I do that it won't restart UNLESS I shut off the UPS. Then, when I turn the UPS back on the Mac starts up immediately without me pushing the power button.

Any other suggestions?

PS: to clarify, my Energy Saver System Pref is NOT set to "Restart automatically after power failure."

Try pluggin your machine straight into the wall bypassing the UPS and unplug any interface the UPS has with your machine. Also it might be worth checking or replacing your internal clock battery.