Chosen Solution
imac 27’ put sd card in optical drive by mistake tried to get it out nothing would work so i opened it up pulled out optical drive got sd card then put it back, then realized the fans were going full speed checked wiring nothing had come of tried smc and some others still nothing run hardware check and found a problem with the hardware error code 4SNS/1/COOOOOO8:TOOP–124 and fans full speed
It sounds like you’ve dislodged one of the temperature sensors. On the newer machines they are a bit tricky. It has a flat side that lays on the drive, with a holder to keep it in place. I had a tough time with the one on the hard drive. Stick the holder on first and using kapton tape secure it in place then insert the sensor. Mine had an added piece of foam on top of that that was taped down. I really don’t like these sensors.
I don’t know about taking apart the iMac but getting an SD card out of the iMac I had to do last night. I used a paper large clip with one end bent in hook and a butter knife to open the felt, A flash light to see the card position. I was able to pull the SD card to the slot and through the felt and out without opening it up at all. I talked to the Apple Store tech and they would charge up to $300 for parts and labor.
