Random question-mark boot, after deleting opencore legacy patcher

[gsinned8]

Hello guys,
I installed opencore legacy patcher on my MBP 2017 13" Intel-based (function keys) a few weeks ago and used Sonoma that way. Everything went smooth, even though it was my first time doing something like that in the macos-roam.
I decided to remove opencore legacy patcher and get back to my original state.

My current problem:
After doing everthing according to the official instructions, I managed to reinstall macos ventura natively through the internet recovery. BUT, every now and then, my macbook can't find my Macintosh HD for some reason and I land in the "questions mark boot menu"... I reinstalled macos 2-3x now already via Internet recovery. I managed to get inside the system, even after the the question mark error, there is a workaround for that. But I want to solve this problem, so I can sell the MacBook without such issues... I also did the First Aid many times. Unmounted the EFI and deleted the required folders (according to the official instructions).

I suspect that I did something wrong with the EFI. What drives me crazy is that after I do my workaround around the question mark boot (not recognized Macintosh HD), the MacBook works. I can restart multiple times. It keeps working. But if the macbook remains off for more than 20 minutes, it is almost 100% certain, that the question mark boot will come up...
Maybe I needed to deactivate some features from the opencore legacy patcher, before deleting it? I didn't really check, what it actually does to the bootloader and such stuff. Im very interested in such things, but didn't pay enough attention in a curcial moment I guess...

I just dont know what to do at this point anymore. Ask me anything, if you have questions regarding my issue. Excuse my english please
Im not shy in terms of trying out more technical stuff, since I am doing an apprenticeship as an system engineer. So you are very welcome to go into details.



Kind regards,

gsinned8

 

[bogdanw]

Reset NVRAM
https://support.apple.com/HT204063

If you really want a clean Mac, download Ventura, make a bootable installer, boot from it, erase the internal drive and install Ventura.
How to download and install macOS https://support.apple.com/102662
Create a bootable installer for macOS https://support.apple.com/101578

 

[Fishrrman]

Agree with post above.

When you went to re-install, did you erase the ENTIRE drive beforehand?
(you may have done this, but didn't see mention of it above)
If not, go back into internet recovery and start over.

VERY IMPORTANT STEP:
After you boot to internet recovery and the utilities load, open disk utility.
You MUST go to the "view" menu, and choose "show all devices".
(if you don't do this, you can't "see" or erase the internal drive)

Once you do this, look at "the list on the left".
The "topmost" item is the physical drive inside.

Erase this to APFS and quit disk utility.
Then open the OS installer and start clicking through.

 

[gsinned8]

I have tried everything you guys told me.
I still get this "question mark"boot after some time.

 

[bogdanw]

Maybe it’s a hardware problem. Did you replace your hard drive or made other upgrades?