I have a 2011 21.5” iMac that still works great with the memory upgraded to 16 GB and an external SSD running the OS. I’m thinking of mounting it to a wall so I can view market charts on it during the day and using it as a music/photo player at night. I looked up a few videos and installing an internal SSD seems doable, plus it’ll give me a chance to swap out the failed SuperDrive and clear out dust that’s accumulated around the fan over the past 7 years. While I’m in there, is there anything else that should be upgraded to help it run for another few years? I noticed one of those circular watch-type batteries inside in the video. What are the other potential points of failure that’ll keep it from running into the future? Also, since it’ll be running primarily off an SSD, would it be better to turn it off periodically or is it okay to leave it running for days on end, just putting the display to sleep at night?