I recently removed the ram from my iMac & replaced it with the stock 4gb sticks. I then did an internet restore (to lion), realized I could not upgrade direct to high Sierra, then used a boot ssd drive to install high Sierra (no migration). The problem still persists (but did not show up in lion.). I wouldn’t read to much into the failure for the problem to show up for the brief time in lion as it is a somewhat intermittent problem (and the computer was warmer.)
One of the reasons I did the scorched earth install attempt and changed out the ram is I have given up and purchased a new iMac.
I intend on posting a link on the for sale forum here soon to sell my 2011 iMac for parts, stating the known issues for any interested buyer.
One of the reasons I did the scorched earth install attempt and changed out the ram is I have given up and purchased a new iMac.
I intend on posting a link on the for sale forum here soon to sell my 2011 iMac for parts, stating the known issues for any interested buyer.