MP 1,1-5,1 MacPro 4,1 always boots after plugging in the powercord. No matter what the energy setting is.

[ThomasFlips]

Hi readers, my first post here on Macrumours. I have a couple of Mac Pro's 4,1 flashed to 5,1 for different usages.
One of them has this weird issue where it ALWAYS boots up after i plug in the powercord.
I don't like this because that means that it will boot after a power failure and we don't want that.

1. I have made sure the energy settings in prefs are not on auto boot after power failure. Not in any of the operating systems.
2. I have did soooo many 5x NVRAM resets for several reasons
3. I have replaced the PSU
4. I have replaced the GPU
5. I have replaced the CPU's
6. I have replaced the CMOS battery
7. I have replaced RAM
8. I have it running Open core (LP) Monterey , Ventura and Windows 11 with an AMD RX580 8GB and 128 gb RAM if that's even relevant.

I now have a backup logic board ready to go in there but I read somewhere that it is possible to rebuild the bootrom.
People are referring to a user called Tsialex to whom i cannot send a message yet seen my 'virginity' on this forum

There you go, I hope this makes for an interesting (first) post / case. Many thanks in advance!

 

[tsialex]

Did you double checked the RTC battery and RTC battery socket for damage? Powering up after the PSU is connected to the mains is a classic signal of no RTC battery.

I'll send you a PM.

 

[ThomasFlips]

Wauw talk about quick! Tnx

 

[tsialex]

Don't forget to inspect the RTC battery socket for damage.

 

[ThomasFlips]

Don't forget to inspect the RTC battery socket for damage.

Good tip. Never inspected that!

 

[ThomasFlips]

Ready for a good long laugh? It was that stupid little sticker on the CMOS battery that somehow managed to stay on. I never noticed because time and date are displayed correct and all other features seemed to work. I also just changed those on all my macs recently and yes, there I have taken that pesty little sticker off.
Thanks to Tsialex who adviced me to check the battery socket for damage I popped the new battery back out. Djeez, now I feel like a newbie allright 😅