Walk-in norlake freezer

if the temp is 10f compressor is fine, just need a tune up, call a specialist.

If your chest freezer is less than 50 years old, it does not have a fan. Cooling coils contact inner walls of freezer compartment, warm coils dissipate heat through outside walls of freezer. If compressor runs, temp is 30+ degrees, gasket is OK, lid not left open, then you have one of two contions: 1. Low capacity compressor 2. Refrigerant leak. Solution to either is to replace freezer. (My opinion: Don't get a Kenmore brand, which generally ties you into poor warranty and slow and poor service.) No matter what brand name is on the freezer, it is most likely manufactured by Electrolux (in St. Cloud, MN) or Haier (from China). Look at the model / serial number plate before purchase to see where it was manufactured. Yes, the USA manufactured ones are better. (and I'm not just saying that because the plant is less than 15 miles from where I am sitting right now)

Normally freezers are kept at zero. Most health departments will not allow the temp to be higher than plus 10. If you want to store ice cream, you need to be at minus 10 degrees to minus 15 degrees.

let me know if I can be of any further help.

You have to defrost the coil by turnning of the unit and to make it faster leave the inside fan/s running.But if it's building up ice and the fan/s inside works ,is most probably that the unit is low in refrigerant(freon) , or the defrost system is not working.

I've worked on freezers for over 20 years and have never heard of a compressor going bad because the door was left open. think about a second opinion.
Also, has the cooling coil inside the box developed and frost or ice build up? If so, it needs to be completely defrosted. If you defrost it manually, use a hose hooked up to hot water. Kill all power and hose all build up off. Remove the sheet metal housing ends and be sure there is no ice inside there too. I would go in this direction first.
IN order to kill a compressor under this condition, something really strange must have happened as anything is possible in a refrigeration system. Good luck and hope this helps.

As long as the temp. stays around 5+ or 5- of 0 degrees everything should be okay.

I assume there is no manual control for setting temp. so the thermal sensor or control circuit has failed and it is just staying at its maximum.  You will probably get more help from the manufacturer but their website is somewhat disjointed; looking for contact info for your product ends at one point and then shifts to their scientific product line.
The only general contact info I found is here:
Nor-Lake 
You will in any case need to have the correct model number at hand since the subject line doesn't sound like your freezer. 

Depends on the product you want to keep in the freezer. Usually you want to try and stay between 0 and +10 degrees for most items. Ice Cream must be -10 degrees minimum. Any warmer and it won't keep. Hope this helps.

Good Luck

YES GOOD ADVISE . ALWAYS START WITH THE BASICS. IS EVAPORATOR COIL CLEAN AND CLEAR? ALL EVAP FANS RUNNING? DRAIN PAN CLEAR? IS STAT CALLING FOR COOL? IS OUTDOOR COND COIL CLEAN? IS OUTRDOOR FAN RUNNING WITH NO PLAY IN BUSHING? DO RUN AND START CAPS TEST GOOD? DOES CONTACTOR LOOK GOOD? THEN TRY TO CATCH UNIT WHEN TEMP IS ABOVE DESIRED SETTING. FIRST TEST STAT. IS IT OPEN OR CLOSED? IF BOX IS HOT AND ITS OPEN THEN PROBLEM IS STAT. IF STAT IS CLOSED AND OUTDOOR FAN IS NOT RUNNING THEN COMPRESSOR PROBABLY OVERHEATING WHEN FAN QUITS. CHECK FOR VOLTS TO FAN GOT VOLTS? FAN IS BAD. NO VOLTS? TRACK BACK TO SOURCE OF POWER ( CONTACTOR) AN R22 BOX AT 52 PRESS IS NOT TO BAD ON START UP ON A HOT BOX BUT COULD BE HIGH ON 502 408 OR R12 STUFF TYPE OF REF IS DEFINITELY IMPORTANT. GOOD LUCK

They are usually mounted on the front panel of the evaporator or mounted on the wall behind the evaporator.There is a possibility that the temp. control is at the condenser,and the sensing bulb was slipped thru the wall.Look for the bulb at the back of the evaporator and follow the cap tube.