iMac 27", late 2012 reboot loop after chime, no AHT no recovery
Hello all, hope I can get some feedback here.
My iMac is basically stuck in a loop which is: power on, chime kicks in, apple logo shows up (with progress bar) then few seconds (10-15) and it reboots and we are back to point one (chime etc etc.)
Things I have tried so far:
1) Reset PRAM and NVRAM several times , no difference
2) SMC reset, unplugged for a minute, plug back, no difference
3) Tried to access recovery and internet recovery, same story, progress bar to approx 50% then reboot, for internet recovery, it actually shows the globe but after a few minutes of progress bar it reboots.
4) Tried to boot from USB (holding shift works and brings up the selection menu with wifi etc etc, keyboard and mouse work properly), after selecting the drive, about a minute of progress bar and then reboot
Only once at the begin I did receive an EFI error
Error:8000000000000003, Cannot load 'EFI/Drivers/TestSupport.efi'
Status: 0x00000003
Will try next https://github.com/upekkha/AppleHardwareTest
Any suggestion?