Is it possible to downgrade a bootrom on MacPro6,1 to a older version? I have read a bunch about SMCFlasher tool and How to downgrade SMC firmware (which doesn't seem valid anymore) amongst others, but before I try something irreversible I want to ask if this is the best way to do so.
The problem I'm facing is that I have a MacPro6,1 with errors PFM006 and PPN001 resulting into the CPU going into safe-mode. I have a gut feeling that this is due to the bootrom being incorrectly updated. The current version of this bootrom is at 4126.96.36.199. I have another MacPro6,1 which has the bootrom currently is on 132.0.0, but both have the same SMC version of 2.20f18 and Illumination version of 1.4a6 (if that makes any difference).
I'm not sure if the bootrom and SMC go hand in hand or not, I'm still learning quite a lot about this as you might be able to imagine.
So, therefor my question: Is there some way I can downgrade the bootrom? Can I "copy" it from my other MacPro6,1 and install it on the faulty MacPro6,1?