Freezer acted dead

Lost all the food. Cleaned out the insides. read some Q and A on this freezer online. Took apart the inside panels...found the schematic on the back corner of the freezer. Eliminated the themostat and fan as the problem. Located online the manual as my wife lost the original paperwork. Gambled the control unit was the problem. Ordered it. It arrived ontime. Installed it. Freezer ran. Put the freezer back together. The thermometer I bought a long time ago said it was at 30 degrees below zero. I adjusted it up to 20 below and it has been running great. Thank You.