Late 2013 iMac 27" with 3TB fusion drive. Crazy problem here. iMac crashed tonight then would not boot up for nearly 10 minutes. Just before this happened, DriveDx showed a temperature problem with the SSD portion of the fusion drive. The mechanical drive is perfectly fine. It's up again after being powered down for a while, but it's getting hot again. (See attached screenshot). Looks like I might have to replace it, since the wonky behavior affects the rest of the system as long as it's there. I'm looking for other suggestions to check. It's odd that the SSD is running so hot, there's nothing running that would run up the system temperature, and there's no mechanical parts (like bearings) to fail. I manually turned up the fan and it roars away, so the fans are working. Any ideas?