After months of trouble-free operation (including an OTA update to Sequoia 15.6) my Mac has stopped cold booting. On startup I simply get a black screen and everything is unresponsive, including keyboard(s) (via USB hub). If I boot with opt key I don't get the light grey screen I should (GOP mod to firmware) but get the same icons on black (all grey disk icons and EFI boot). The keyboard does not work so it just sits on that screen until eventually it restarts itself back to the black screen (no caps lock light either).
If NVRAM is reset (4 chimes) I can boot as normal to Mojave. If I restart from Mojave I can use option key to get bootpicker screen (grey now as expected) and keyboard functions and now I can select EFI boot and then black screen OC picker and I can select Sequoia and boot just fine. If I restart from Sequoia all is good and it boots as expected.
Once mac is shutdown and then later/next day restarted this all begins again. Sometimes holding option key will give me a grey screen, in which case I can select EFI boot and then OC bootpicker select Sequoia drive. Other times the bootpicker screen is black and then I have to clear NVRAM due to keyboard not operational and get back to Mojave and then repeat as above.
I have changed nothing in configs since it was running perfectly. What happens now as described is 100% repeatable - from a cold boot or a restart. One works, other doesn't.
Once I have got back to getting the grey bootpicker screen (Apple) then EFI boot can be selected (keyboard is functional) and I am good till next shutdown. If I get the black bootpicker then my Mac is stuck as in this mode keyboard doesn't not work and shutdown must be forced with power.
I have no idea what the black bootpicker screen on option-boot is. It looks identical to the apple one but on black. And once it comes up I am screwed.
I have gone as far as to re flash firmware but to no avail.
So:
If I boot normally from power off: black screen.
If I boot from power off with option - and get grey bootpicker -> select EFI boot -> select Sequoia -> boots fine
If I boot from power off with option and get BLACK bootpicker (no idea why) -> I have no keyboard -> not able to select EFIboot and so no boot. Only way to get grey bootpicker again is via NVRAM reset and Mojave.
When Sequoia is running and I do a warm restart it boots fine by itself without needing book picker.
Any ideas?
Thnx
If NVRAM is reset (4 chimes) I can boot as normal to Mojave. If I restart from Mojave I can use option key to get bootpicker screen (grey now as expected) and keyboard functions and now I can select EFI boot and then black screen OC picker and I can select Sequoia and boot just fine. If I restart from Sequoia all is good and it boots as expected.
Once mac is shutdown and then later/next day restarted this all begins again. Sometimes holding option key will give me a grey screen, in which case I can select EFI boot and then OC bootpicker select Sequoia drive. Other times the bootpicker screen is black and then I have to clear NVRAM due to keyboard not operational and get back to Mojave and then repeat as above.
I have changed nothing in configs since it was running perfectly. What happens now as described is 100% repeatable - from a cold boot or a restart. One works, other doesn't.
Once I have got back to getting the grey bootpicker screen (Apple) then EFI boot can be selected (keyboard is functional) and I am good till next shutdown. If I get the black bootpicker then my Mac is stuck as in this mode keyboard doesn't not work and shutdown must be forced with power.
I have no idea what the black bootpicker screen on option-boot is. It looks identical to the apple one but on black. And once it comes up I am screwed.
I have gone as far as to re flash firmware but to no avail.
So:
If I boot normally from power off: black screen.
If I boot from power off with option - and get grey bootpicker -> select EFI boot -> select Sequoia -> boots fine
If I boot from power off with option and get BLACK bootpicker (no idea why) -> I have no keyboard -> not able to select EFIboot and so no boot. Only way to get grey bootpicker again is via NVRAM reset and Mojave.
When Sequoia is running and I do a warm restart it boots fine by itself without needing book picker.
Any ideas?
Thnx
