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AleksPs
User level: Level 1 (10 points)

Mac Pro Late 2013 won't start

I have a late 2013 Mac Pro. These days it has problems with turning on. When I press power button button panel light turns on, LaCie External HDD starts, but MAC doesn't. Bluetooth keyboard and muse are not connecting neither.The most interesting part is if I leave it for 24 h (no less otherwise will not work) unplugged it starts normally. What can be the issue? Is there a way to solve it easily?


Power cord is OK.

From MACOS no issues were identified when I checked system information

SMC I cannot reset as bluetooth keyboard doesn't work until it will not boot.


Thanks!

Posted on Jan 2, 2020 4:36 AM

10 replies

Grant Bennet-Alder
User level: Level 10 (148,617 points)

Jan 2, 2020 7:57 AM in response to AleksPs

Another way to effect SMC Reset is to disconnect AC power cord, press and hold the power-on button for a quarter minute, restore AC power cord, wait a quarter minute, then attempt to power on.


Because there is an 'always-on' power supply inside Mac Pro, you may experience minor arcing when you restore the power cord. This is normal, not a defect.


One other usual simple fix was to check the Coin Cell battery for at least the minimum 3 volts. However on these Macs, getting access to the the coin cell battery is a exceptionally complicated.

BDAqua
User level: Level 10 (251,965 points)

Jan 2, 2020 7:16 AM in response to AleksPs

Sounds like a blown capacitor, or Ground Loop. but have you tried it with nothing else plugged into it?

Grant Bennet-Alder
User level: Level 10 (148,617 points)

Jan 3, 2020 10:15 AM in response to BDAqua

Those are also the classic symptoms of dead coin-cell battery, for Macs as old as the PowerMac G3.

BDAqua
User level: Level 10 (251,965 points)

Jan 4, 2020 8:44 AM in response to AleksPs

Well, that is the exact symptom of a charge bleeding down after a bit,& blown caps a a major cause of that, Ground Loops another cause.


On Pram, that is what tells the Mac how & where to boot from.

AleksPs Author
User level: Level 1 (10 points)

Jan 3, 2020 3:20 AM in response to Grant Bennet-Alder

Today I have managed to turn on since it was unplugged for 24h. I performed HW test (holding D at boot) but no issues will identified.

I have noticed that when MAC will not boot, fan is not working neither.


Why Coin Cell battery may e cause of the issue?

I would really like to understand the cause and how to solve it.

AleksPs Author
User level: Level 1 (10 points)

Jan 4, 2020 2:45 AM in response to Grant Bennet-Alder

My doubt is why ever this battery prevents from booting? In my understanding it is only required to maintain some data in PRAM, but should not prevent from booting.


Since changing a battery is really a tough task in these MACs, I want to be sure it's the only way to solve it.

AleksPs Author
User level: Level 1 (10 points)

Jan 3, 2020 3:18 AM in response to BDAqua

I have tried in all ways. no result

BDAqua
User level: Level 10 (251,965 points)

Jan 3, 2020 11:46 AM in response to Grant Bennet-Alder

Thanks, I know about the older Macs, but haven't actually seen it prevent booting in later Macs. :)

AleksPs Author
User level: Level 1 (10 points)

Jan 4, 2020 2:41 AM in response to BDAqua

It starts normally each time I keep it unplugged for some time (approx 24h), so I don't think this is some power management issue like capacitor.

Originally posted at discussions.apple.com/thread/251001228