Why did my computer screen go blank and will not restart in either nor
I started having "kernel panic" issues in bringing the computer out of sleep mode (requiring a restart) and worked with Apple tech support for several weeks, mostly around software solutions. I ran Apple Diagnostics several times which reported "No issues found." Reinstalled OS. Problem persisted
Apple support determined it was hardware and I took the computer to the local Apple Store where the Logic Board was tested and found to be OK but apparently there were other (unidentified) indications that suggested replacing the Logic Board was in order and a new one was installed.
When the "kernel panic" issues continued under normal use, I returned the computer to Apple for further tests and when no other hardware issues could be found and the "kernel panic" issues continued, Apple refunded the price of the Logic Board and left the new board in the computer.
The “kernel panic” shut-down/restart problem persisted following the second trip to the Apple Store and then after about a month and seven "kernel panic" episodes, the screen went blank. I was able to restart it once in SAFE mode and ran the Apple Diagnostics program which showed "no problem."
At this point:
· Although there is some indication something is going on, the computer will not start normally and the screen remains blank).
· It will not start in SAFE mode (screen blank) and of course I cannot run Apple Diagnostics.
Thank you for your help.