I've noticed if my unit it cold it won't turn on. I'll hit the button and it will shut off before it boots up. I'll have to set it by a heat source for a while to warm the shell before it boots and stays on. Just wondering if there is a fix for this.
Mac Pro
Which model Mac Pro?
What graphics card?
What version of macOS X?
It's a 2008 model Mac Pro,
Graphics card: ATI Radeon HD 5770 Graphics Upgrade Kit for Mac Pro (Mid 2010)
And I'm running Mac OS X 10.6 Snow Leopard
Can you boot holding down the Alt/Option key? This invokes Startup Manager, a routine that is all in ROM, that draws an Icon for each potentially-bootable Volume. When the watch cursor goes away, the Eject key on the keyboard goes "live" and can be used to open the DVD to insert the 10.6 DVD. Can you boot from the 10.6 DVD?
I've got the same Mac Pro and the same problem.
It is 17 degrees Celcius right now and still too cold to boot.
When I hit the power button, it emmediately shuts down.
I just have to wait until it is about 20 degrees.
Or put a heating fan in front of the computer.
Strange thing. I think the logic board earley 2008 has a temperature sensor that is too sensitive.
It was designed for high temperatures I think.
I have never (6 years now) heared the cooling fans running any faster.
It won't get overheated.
Replacing the logic board is the only option.
I'va got an 2007 Mac Pro also, that runs fine, every day.
My MacPro has booted!
It is 20 degrees Celcius now.
Everything is working fine.
So I better leave the heating on at night.
(until I decide about updating the logic board, or the whole Mac.)
I have the same problem - I figured it out this winter as per last year my 2008 Mac Pro won't boot unless it's warm. As long as it's cold it just beeps and shuts down. Opening the side and gently warming with a hair dryer is the only way to boot!!! Any idea if the temp sensor is to blame?
Ik have solved the problem.
Take out the powercord, so the motherboard is completely powerless.
The next day I plug in the powercord and booting is just fine.
So now I make a habbit of unplugging the powercord when shutting down.
Never had the problem again.
Ik think some sensors on the motherboard are still working when shutdown and those sensors are messed up.
Mayby I wil make a powerswitch on my outlet.
Sideaffect is less power consumption!!
The way to do SMC Reset, which is what you are doing only the long method, is to unplug everything, yes, but then hit power button on front for 10 seconds. Wait a minute and reconnect the display cable, keyboard and mouse and power cord.
I would invest in a 900W / 1500VA like the CyberPower SMART or Pure-Sine model for about $199, look at what else is on the same circuit, what type of surge protector you are using if any.
2008's have had strange power issues.
But do an SMC Reset, zap the PRAM (reset the startup disk control panel as it will have to look each time) and see how it works.
Still easier to pull only the powercord. And reconnect when using the computer.
All settings remain.
Prevents you from buying a new computer.
When it runs it is still a fine machine.
My computer shuts won't boot if it's cold
