[Solved] Please help! upgrade stuck at "MACH reboot", main pc went brick

[cmn699]

well i just did that, i don't see no error message
but when i restart, it hangs at the exact same spot: "MACH .. Reboot"

As far as I know from my own personal experience, this error can occur if the Processor finds the "Kernel" unacceptable to boot. The Kernel boots only if it has the Right kexts in the right places , and right configurations for the kernel(in this case HS kernel in the USB installer) to boot.

So, every part of CLOVER is a suspect . Since you have tried a lot of changes and failed, try the following:

• I suggest changing the Mac Model to something closer to 2015-17 in the SMBIOS.
• You can try that in CBM screen Options>SMBIOS and change imac14,2 to iMac18,3

 

[vulgo]

well i just did that, i don't see no error message
but when i restart, it hangs at the exact same spot: "MACH .. Reboot"

Remove all of those non-apple kexts in that image then re-run kextcache. Or start with FakeSMC + plugins, try booting, remove some more etc.

 

[Pepperish]

Remove all of those non-apple kexts in that image then re-run kextcache. Or start with FakeSMC + plugins, try booting, remove some more etc.

yay! i finally got in to the system!!!! i have deleted everything that was suggested by that command and it loaded to the system. i don't know the theory behind it tho.
many many thanks to you @vulgo @cmn699 and @originalmagneto, you guys are the best.

but the bad news is the happiness didn't last every long. i got in the system, and tried to install new graphics
driver. but it rebooted into black screen? any idea on that?

 

[BreBo]

but the bad news is the happiness didn't last every long. i got in the system, and tried to install new graphics driver. but it rebooted into black screen? any idea on that?

Fix for failure NVIDIA Web Driver on High Sierra, black screen, panics.

 

[Pepperish]

Fix for failure NVIDIA Web Driver on High Sierra, black screen, panics.

thanks!
i have actually made another thread here, i made some changes and it didn't work, but today it jsut worked magically with no alteration. lol, dunno why but i am happy with the current result