MP 1,1-5,1 Mac Pro 5,1 Power Switch

[LookToWindward]

Hi,

The Power Switch is not working correctly on my Mac Pro 5,1. If I have the power off and the mains power cable pulled out, when I plug it back in again, power is applied to the whole machine without pressing the button. Is this a known fault? Any fix available?

All the Best
Dave

 

[tsialex]

Known fault, easily found with the forum search, when the BR2032 RTC battery is spent, the SMC starts the Mac Pro PSU automatically when the power cable is connected to the mains.

Replace the BR2032 battery.

 

[LookToWindward]

Known fault, easily found with the forum search, when the BR2032 RTC battery is spent, the SMC starts the Mac Pro PSU automatically when the power cable is connected to the mains.

Replace the BR2032 battery.

I thought of that, the first thing I did was replace the battery. I did that before putting power onto the box, the old one may of been ok. Maybe it isn't sitting correctly?

 

[tsialex]

Did you follow the correct procedure and did reset the RTC? See the Apple Technician Manual.

 

[LookToWindward]

I'm not sure what document you are referring to? I followed the instructions in the Apple Technical Guide page 158?
It just says to slide the old battery out and the new one in with +ve side face up

 

[tsialex]

Whenever you replace the RTC battery, you need to reset the RTC.

Read around pages 30 to 32 (for the mid-2010/mid-2012 Apple Technician Manual 2012 edition, different pages for the early-2009) and follow the described procedure.

 

[LookToWindward]

Thanks, works ok now. I must have changed 4 or 5 batteries and never had this problem before, I guessing the old battery was removed for 20 secs but power cord was connected. This time, the power cord was out when I did it, so it didn't reset. Thanks again

 

[haralds]

Make sure, it's a BR and not CR. CR is supposed to work, but my brother ran into flaky start behavior until he put in the BR2032.

 

[LookToWindward]

Make sure, it's a BR and not CR. CR is supposed to work, but my brother ran into flaky start behavior until he put in the BR2032.

Really? I've not seen this before, I've been using CR batteries and no problems