iMac 27 screen randomly turns off/on
iMac 27 mid 2010. Screen randomly turns off/on after OS's boot. I tried to replace the inverter board and the power supply from fine working iMacs, tried to connect it to working Macbook as external monitor, formated HDD and reinstalled with different versions macOS's, also tried the lcd display cables they seem to be fine. So the problem remains. Any ideas? Thank you!
Is this a good question?