Need help to understand how MacPro1,1 self-powers on & off?

[timidhermit]

I am a new owner of a vintage MacPro1,1. The Mac Pro is in good shape and passes the Apple Hardware Test without problem.

I recently observed a strange behavior about how the Mac Pro self-powers on after shutting down. Here is the situation:

If I shut down the system from Mac OS X, it shuts down normally. I then turn off the power bar to which this system is connected. When I turn on the power bar later, the Mac Pro stays shut off until I press the power button to start. This is what I expected as NORMAL BEHAVIOR.

Now, if I manually shut down the system by pressing power button at the boot screen (by holding down the option key), the system appears to shut down normally. However, if I then turn off the power bar to cut power to the system but then later turn on the power bar again, the Mac Pro automatically starts up without me needing to press the power button. Is this NORMAL or ABNORMAL?

By comparison, I tried this scenario out on my friend's MacPro5,1. The above does not occur. The Mac Pro just stays being powered off until the power button is pushed.

Is there some non-volatile system parameters I need to reset? I reset the PRAM and SMC already.

Please help!

 

[owbp]

Never tried to do something similar, so sorry for not answering your main question.
But i just wanted to ask you have you checked if both Macs, yours 1,1 and friends 5,1, have the same Energy Saver settings?

 

[timidhermit]

Thanks for the tip. In BOTH system, this option was turned off.

If it is too much trouble, may I kindly ask you to try out what I did above to see if your Mac behaves the same? I am not familiar with the Mac Pro hardware. I tried to research this online but unable to find any solid info, probably because I am not phrasing my inquiry correctly.

Never tried to do something similar, so sorry for not answering your main question.
But i just wanted to ask you have you checked if both Macs, yours 1,1 and friends 5,1, have the same Energy Saver settings?

 

[owbp]

Ok, i will as soon as i finish few things. Shouldn't be more than 15-20 minutes.

Just help me with something that i didn't understand:

if I manually shut down the system by pressing power button at the boot screen (by holding down the option key)

You boot into the boot screen, where you choose OS X, Win or Recovery boot (you don't let it load system) and then you shut it down by holding the power button? Did i understand this correctly?

And for how long do i need to keep power bar turned off (or unplugged from the wall)?

 

[timidhermit]

owbp, THANK YOU for helping!!!

Am I correct that you have a MacPro1,1?

You are correct, I have dual boot. The boot screen I was referring to is the one where you choose which OS to boot. At this screen, the scenario occurs if I do a "forced" shut down by pushing the power button until I hear the click and the system shuts down (including all lights and fans).

The power cord for my Mac Pro is connected to a power bar. The power bar itself has a switch. Once the Mac Pro is powered off (from the previous shutdown), I then turn off the power bar to "cut" power to the Mac Pro. When I turn on the power bar (without touching the Mac Pro), the Mac Pro will self-power itself on in about 5 seconds.

Regarding the time I kept the power bar turned off, I turned two scenarios: one at 10-15 seconds, one at 1-2 minutes.

Ok, i will as soon as i finish few things. Shouldn't be more than 15-20 minutes.

Just help me with something that i didn't understand:

You boot into the boot screen, where you choose OS X, Win or Recovery boot (you don't let it load system) and then you shut it down by holding the power button? Did i understand this correctly?

And for how long do i need to keep power bar turned off (or unplugged from the wall)?

 

[owbp]

Am I correct that you have a MacPro1,1?

Yes i do, the one in the signature.

I've tried all possible scenarios (i too have power bar with on/off switch), even to shut it down (power button and power bar) during OS running, and it won't turn on by itself.
The only time it turns on after cutting the power directly from the wall (with a bar's switch) is if i have that option checked in Energy Saver (Start up automatically after a power failure).

Sorry for not being able to help you, but I'm sure that you'll hear something useful from the guys here with more experience in Macs soon.

 

[timidhermit]

Thank you for trying. I am now very worried.

Yes i do, the one in the signature.

I've tried all possible scenarios (i too have power bar with on/off switch), even to shut it down (power button and power bar) during OS running, and it won't turn on by itself.
The only time it turns on after cutting the power directly from the wall (with a bar's switch) is if i have that option checked in Energy Saver (Start up automatically after a power failure).

Sorry for not being able to help you, but I'm sure that you'll hear something useful from the guys here with more experience in Macs soon.

 

[owbp]

Let's see what others have to say about this, but I wouldn't worry.
If it is stable and temperatures are okay there's nothing wrong with it.

Btw, I was trying all that from El Capitan with SIP disabled. Don't know if it has anything to do with OS or the way it writes those things in PRAM...?

 

[timidhermit]

Anyone help?

 

[ITguy2016]

Anyone help?

I don't have a 1,1 but I do have a 3,1 if you want me to test it for you.

 

[timidhermit]

Yes, please try it out as the hardware of MacPro3,1 may be close enough.

I am suspecting that this is an SMC controller to managing the power on state when power is cut off from the MacPro with a power bar.

I don't have a 1,1 but I do have a 3,1 if you want me to test it for you.

 

[ITguy2016]

I am unable to replicate the issue you describe where you power off the system from the boot selection screen. If I press and hold the power button until the system powers off and then disconnect and reconnect the power cord (after a period of time ranging from seconds to a minute) the system remains off until I power it on with the power button. The same behavior occurs if I just pull the power cord instead of using the power button. The system does automatically power on if I'm at the OS and pull the power cord (after enabling this option in System Preferences).

 

[timidhermit]

Thank you, ITguy2016. I am just puzzled over this. I am wondering if this can be related to my Windows partition which I use to dual boot. Anyone?

I am unable to replicate the issue you describe where you power off the system from the boot selection screen. If I press and hold the power button until the system powers off and then disconnect and reconnect the power cord (after a period of time ranging from seconds to a minute) the system remains off until I power it on with the power button. The same behavior occurs if I just pull the power cord instead of using the power button. The system does automatically power on if I'm at the OS and pull the power cord (after enabling this option in System Preferences).