Replacing Failed HDD with SSD in a 21.5" iMac

Mein Problem

The computer had worked very slow for months so I ended up redeploying it in a hobby room. After a month it failed to boot, and recovery mode wouldn't work and First Aid failed.

Meine Reparatur

The replacement of the HDD and the application of the adhesive strips went EXACTLY as described (including the slip of the display one other user experienced.) Recovered from that easily and the iMac works great and is MUCH faster! Slow performance might have been due to the failing HDD. The teardown was about an hour; the rebuild about 45 minutes, the adhesive placement about 30 minutes, and another 30-40 minutes for OS X installation. Very smooth.

Mein Rat

Be patient and follow the guide. Read it several times before you begin. Worst part was reconnecting the new SSD to the connector...very little slack on the cable. Make sure everything works before you remove the adhesive strips' backing.