For 2012 or earlier Mac Pros which aren't fixed by a standard SMC reset, use the SMC reset button on the motherboard...
Shut down. Unplug the power cord. Open the Mac Pro side access panel. Just below the drive 4 sled and next to the top PCI-e slot is a small button labeled SMC. Press and hold it for 10 seconds. Close the side door. Reconnect the power cord. Wait 5 seconds. Start the Mac normally.
Also try a PRAM reset, if this doesn't help.
I usually write a blog post about once a week. The latest post can be viewed here: Deranged Rants: Many of them are totally feral, unhinged, and totally irrational. (posted 2024-11-13 at 17:55:14). I do podcasts too!. You can listen to my latest podcast, here: OJB's Podcast 2024-08-22 Stirring Up Trouble: Let's just get every view out there and fairly debate them..
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