Chosen Solution
Hi people, Thanks for the help with your sharing. My iMac has been running for about 10 years and got shutdown really, really, really seldom. As other people posted here, it doesn’t boot anymore (loading bar stops, and then it reboots) and the Diagnosis Tool shows that :4MOT/4/400000003:HDD-1376 I’ve understood that this is about the HDD or its fan. Well, I opened my iMac and discovered there’s is no HDD, nor its fan anymore.Indeed, quite a few years back, I’ve asked an Apple Reseller to replace the hard drive with an SSD, and so he did, taping the SSD below the Optical Drive. Could you people help me understand how I might repair this ? Shall I conclude that it is a logic board error ? Thanks to all for your inputs.–Dom
4MOT/4/400000003:HDD is the iMac Intel 27" (Late 2009-Mid 2011) Hard Drive Fan It’s not easy to see as it sits underneath the logic board
To lift aside the logic board follow these steps Installing iMac Intel 27" EMC 2429 Dual Drive Kit (HDD or SSD) which are the same steps needed to lift the logic board off. In Step 33 you can see the top part of the fan unit (mouth)
Carefully lift out the logic board to reach to the back to disconnect the HDD & Optical drive cables (and if present the SSD cable if present) from the logic board. I leave the power cable and just carefully move the board aside to gain access to the fan unit and its screws.
This series requires a HDD sensor to work properly if you’ve removed the HDD or replaced it with a SSD as described in this guide iMac Intel 27" EMC 2429 Hard Drive Replacement iMac Intel 21.5" and 27" (Mid 2011) SSD Temperature Sensor
