Chosen Solution
hello everyone, I have a 21.5 iMac late 2013 model that after 5-10 min of being turned on goes randomly black (LCD, external display and the system itself) like when it goes into sleep and then comes back on asking for password to resume, no restart. Few things and tests worth to mention: The external display also goes black, and sound stops.I changed the internal HDD and also boot it with an External USB disk with a different macOS, same result.the iMac works fine while ON, no other crashes or issues.Ran apple Diagnostics 3 times, “No issues found”. Funny thing is it never happens while in diagnostics mode or after a long time of having finished.In safe mode also happens.All energy and sleep parameters are set off. Issue arises even while moving mouse Any ideas? please share your thoughts. Update (10/06/2020) Any suggestion is welcome, I ran out of trials
Just want to inform the community the problem was into the display, I installed another display and the computer has been running great for days. seems like the LCD has a controller builtin and that part had issues.
