iATKOS | United Kingdom

Not ready to throw the towel just yet (although it's been multiple days of trying). It started with trying to install Sequoia 15.6.1 on my:

• iMac 27" Mid-2011 (iMac 12,2)
• 16GB RAM DDR3 1333Mhz
• NVIDIA Quadro K2000M flashed for boot screen
• OEM LCD Display
• 256GB SSD, 2TB HDD

Sequoia 15.6.1 installed just fine and I read somewhere that this version needs an additional pkg for my GPU called MetallibSupportPkg which I downloaded, and installed (matching the OS and build version) from Dortania's github. However, once I installed the post-installation patches via OCPL, the iMac gets to the login screen but freezes after the password is entered. Booting in safemode or booting having previously reverted the patches (which allows me to get past the login screen) reveals that the pc encountered a problem (and in short): Kernel panic due to division by 0 in windowsServer task traced back to the driver AppleBacklightExpert.

So far, i've tried:

• Resetting NVRAM via opencore bootloader
• Resetting SMC by powercycling
• Installed Sonoma 14.8.1 (same issue with same driver)
• Removing two sticks of RAM
• Opening the iMac and re-seating the LCD cables
• Reverting the patches and installing again (many many times)

IMPORTANT:

I did not do the GPU installation myself, nor do i know the implications of this. I just know that I do not have brightness control and the screen is always on full brightness. I also do not have any color profiles available in display settings, nor is the LCD recognized (just says "Unknown Display").

During my troubleshoot with ChatGPT, it mentioned that the display is not sending EDID which could interfere with the backlight driver not sending any data and causing a division by zero error.

Any and all help is appreciated if you've seen this issue before. My deepest thanks in advance!

LOGS after a freeze, reboot, and boot into safe mode:

panic(cpu 0 caller 0xffffff8026777f83): Kernel trap at 0xffffff7fbac0c7a6, type 0=divide error, registers:
CR0: 0x000000008001003b, CR2: 0x00007fbeee137010, CR3: 0x000000025808c01a, CR4: 0x00000000000626e0
RAX: 0x0000000000280000, RBX: 0x0000000000000001, RCX: 0x0000000000000000, RDX: 0x0000000000000000
RSP: 0xffffffff00097554, RBP: 0xffffffff00097590, RSI: 0x0000000000010000, RDI: 0xffffffa03f8f4b20
R8: 0xffffff99d9e01e20, R9: 0x0000000000000001, R10: 0xffffff99d9e01e20, R11: 0x0000000000000000
R12: 0x0000000000000037, R13: 0x0000000000000000, R14: 0x0000000000000000, R15: 0x0000000000000001
RFL: 0x0000000000010246, RIP: 0xffffff7fbac0c7a6, CS: 0x0000000000000008, SS: 0x0000000000000000
Fault CR2: 0x0000000000000000, Error code: 0x0000000000000000, Fault CPU: 0x0, PL: 0, VF: 0

Panicked task 0xffffff86a71ba1d8: 9 threads: pid 149: WindowServer
Backtrace (CPU 0), panicked thread: 0xffffff99d98040c8, Frame : Return Address
0xffffffff00096ed0 : 0xffffff80266225a1 mach_kernel : _handle_debugger_trap + 0x4b1
0xffffffff00096f20 : 0xffffff8026788520 mach_kernel : _kdp_i386_trap + 0x110
0xffffffff00096f60 : 0xffffff8026777adc mach_kernel : _kernel_trap + 0x55c
0xffffffff00096fe0 : 0xffffff80265bc971 mach_kernel : _return_from_trap + 0xc1
0xffffffff00097000 : 0xffffff802662288d mach_kernel : _DebuggerTrapWithState + 0x5d
0xffffffff000970f0 : 0xffffff8026621f33 mach_kernel : _panic_trap_to_debugger + 0x1e3
0xffffffff00097150 : 0xffffff8026ddaabb mach_kernel : _panic + 0x84
0xffffffff00097240 : 0xffffff8026777f83 mach_kernel : _sync_iss_to_iks + 0x2c3
0xffffffff000973c0 : 0xffffff8026777c67 mach_kernel : _kernel_trap + 0x6e7
0xffffffff00097440 : 0xffffff80265bc971 mach_kernel : _return_from_trap + 0xc1
0xffffffff00097460 : 0xffffff7fbac0c7a6 com.apple.driver.AppleBacklightExpert : __ZN30AppleBacklightParameterHandler21interpolatePanelTableEPKtttjPtt + 0x98
0xffffffff00097590 : 0xffffff7fbac06faf com.apple.driver.AppleBacklight : __ZN16AppleIntelPanelA10setDisplayEP9IODisplay + 0x49f
0xffffffff00097680 : 0xffffff7fbb83dc91 com.apple.iokit.IOGraphicsFamily : __ZN9IODisplay19addParameterHandlerEP25IODisplayParameterHandler + 0xaf
0xffffffff000976b0 : 0xffffff7fbb83dbb2 com.apple.iokit.IOGraphicsFamily : __ZN9IODisplay23searchParameterHandlersEP15IORegistryEntry + 0x6e
0xffffffff000976e0 : 0xffffff7fbb83ea0c com.apple.iokit.IOGraphicsFamily : __ZN9IODisplay5startEP9IOService + 0x604
0xffffffff00097780 : 0xffffff7fbb83a8b2 com.apple.iokit.IOGraphicsFamily : __ZN21AppleBacklightDisplay5startEP9IOService + 0x12
0xffffffff000977b0 : 0xffffff8026ce36a7 mach_kernel : __ZN9IOService14startCandidateEPS_ + 0xf7
0xffffffff00097810 : 0xffffff8026ce315a mach_kernel : __ZN9IOService15probeCandidatesEP12OSOrderedSet + 0xf1a
0xffffffff00097900 : 0xffffff8026ce20bb mach_kernel : __ZN9IOService14doServiceMatchEj + 0x36b
0xffffffff00097960 : 0xffffff8026ce1a0f mach_kernel : __ZN9IOService13startMatchingEj + 0x16f
0xffffffff000979d0 : 0xffffff8026cd9d42 mach_kernel : __ZN9IOService15registerServiceEj + 0xf2
0xffffffff00097a10 : 0xffffff7fbb841579 com.apple.iokit.IOGraphicsFamily : __ZN17IODisplayWrangler19makeDisplayConnectsEP13IOFramebuffer + 0x87
0xffffffff00097a40 : 0xffffff7fbb851f48 com.apple.iokit.IOGraphicsFamily : __ZN13IOFramebuffer14displaysOnlineEb + 0x2e
0xffffffff00097a60 : 0xffffff7fbb854322 com.apple.iokit.IOGraphicsFamily : __ZN13IOFramebuffer4openEv + 0xc1e
0xffffffff00097ae0 : 0xffffff7fbb84a091 com.apple.iokit.IOGraphicsFamily : __ZN13IOFramebuffer13newUserClientEP4taskPvjPP12IOUserClient + 0x17d
0xffffffff00097b70 : 0xffffff7fbcb9deb1 com.apple.nvidia.driver.NVDAResman : __ZN4NVDA13newUserClientEP4taskPvjPP12IOUserClient + 0xb3
0xffffffff00097bc0 : 0xffffff8026cdbe6d mach_kernel : __ZN9IOService13newUserClientEP4taskPvjP12OSDictionaryPP12IOUserClient + 0x6d
0xffffffff00097c20 : 0xffffff8026d4e545 mach_kernel : _is_io_service_open_extended + 0xb5
0xffffffff00097ca0 : 0xffffff802672fe2f mach_kernel : _iokit_server_routine + 0x35ff
0xffffffff00097d00 : 0xffffff80265ff405 mach_kernel : _ipc_kmsg_send + 0x6f5
0xffffffff00097da0 : 0xffffff8026613305 mach_kernel : _mach_msg_overwrite_trap + 0x5a5
0xffffffff00097df0 : 0xffffff80266139f4 mach_kernel : _mach_msg2_trap + 0x444
0xffffffff00097ee0 : 0xffffff802675c92b mach_kernel : _mach_call_munger64 + 0x22b
0xffffffff00097fa0 : 0xffffff80265bcdd6 mach_kernel : _hndl_mach_scall64 + 0x16
Kernel Extensions in backtrace:
com.apple.iokit.IOGraphicsFamily(598.0)[79F2F7E4-E451-35E1-BF22-1EFFA4192888]@0xffffff7fbb839000->0xffffff7fbb867fff
dependency: com.apple.iokit.IOPCIFamily(2.9)[79B622EF-0198-34BC-9D09-186D725B8071]@0xffffff802896b000->0xffffff802899cfff
com.apple.nvidia.driver.NVDAResman(16.0)[879FE28C-BC88-3553-B3C7-1CCFAE357D45]@0xffffff7fbcb99000->0xffffff7fbce12fff
dependency: com.apple.AppleGraphicsDeviceControl(8.1.9)[84CB0373-54F5-3BDF-A76B-6A9538BE7A90]@0xffffff7fbacd0000->0xffffff7fbacd3fff
dependency: com.apple.iokit.IOGraphicsFamily(598)[79F2F7E4-E451-35E1-BF22-1EFFA4192888]@0xffffff7fbb839000->0xffffff7fbb867fff
dependency: com.apple.iokit.IONDRVSupport(598)[351B4E2D-C260-3E0E-AD4C-C215DA3E2248]@0xffffff7fbb88d000->0xffffff7fbb895fff
dependency: com.apple.iokit.IOPCIFamily(2.9)[79B622EF-0198-34BC-9D09-186D725B8071]@0xffffff802896b000->0xffffff802899cfff
com.apple.driver.AppleBacklightExpert(1.1)[D752E161-3B3D-3648-9663-8DE0C690E9A0]@0xffffff7fbac0b000->0xffffff7fbac0cfff
dependency: com.apple.driver.AppleSMC(3.1.9)[B6D333BE-CC32-33DE-99BD-5824A3392BE0]@0xffffff8027d8a000->0xffffff8027da5fff
dependency: com.apple.iokit.IOGraphicsFamily(598)[79F2F7E4-E451-35E1-BF22-1EFFA4192888]@0xffffff7fbb839000->0xffffff7fbb867fff
dependency: com.apple.iokit.IONDRVSupport(598)[351B4E2D-C260-3E0E-AD4C-C215DA3E2248]@0xffffff7fbb88d000->0xffffff7fbb895fff
dependency: com.apple.iokit.IOPCIFamily(2.9)[79B622EF-0198-34BC-9D09-186D725B8071]@0xffffff802896b000->0xffffff802899cfff
com.apple.driver.AppleBacklight(180.9)[FDF17E26-3212-32F7-9BF8-C5F39AD32DB5]@0xffffff7fbac05000->0xffffff7fbac07fff
dependency: com.apple.driver.AppleBacklightExpert(1.1.0)[D752E161-3B3D-3648-9663-8DE0C690E9A0]@0xffffff7fbac0b000->0xffffff7fbac0cfff
dependency: com.apple.iokit.IOGraphicsFamily(598)[79F2F7E4-E451-35E1-BF22-1EFFA4192888]@0xffffff7fbb839000->0xffffff7fbb867fff
dependency: com.apple.iokit.IONDRVSupport(598)[351B4E2D-C260-3E0E-AD4C-C215DA3E2248]@0xffffff7fbb88d000->0xffffff7fbb895fff
dependency: com.apple.iokit.IOPCIFamily(2.9)[79B622EF-0198-34BC-9D09-186D725B8071]@0xffffff802896b000->0xffffff802899cfff

Process name corresponding to current thread (0xffffff99d98040c8): WindowServer
Boot args: keepsyms=1 debug=0x100 -lilubetaall -btlfxallowanyaddr ipc_control_port_options=0 -nokcmismatchpanic

Mac OS version:
23J220