Delfield mini freezer for restaurant is not freezing. Unit has power and cabinet fan runs but comp tries to kick on then you here a click and it immidietly shuts off before it can really ever start. Hi side press at 150 low side is 0. Never seen this before.

have you checked the door switch for each door? the lights should still work in defrost mode but not fans or compressor.

with such limited information, I can only answer generic. Most of the time it is because the evaporator fan(s) are not running or the evaporator is frozen over. With further info such as model, serial, or more details on behaviors, I could probably helps some further.

Restaurant Part and More, Parts Town, Heritage Parts. Just google them.

Is your circulating fan working?
Sometimes they stick and need a shot of WD 40 and then work
it back and forth a little until it wants to take off again. Keep me informed
and PLEASE give a Thumbs Up for the effort. The Raz Shack

You have to give more info. What refrigerant, where is the unit located so ambient temps can be considered, is there a cap tube or txv.
http://www.delfield.com/docs/uploaded/del/manuals/DM6000XL.pdf
Try this web site from Delfield. It should be you manual. It says your unit has 404-A. Check it out and let me know if you need more info.

Call Rick at Restaurant Parts and More. He can get you just about anything if you have model and serial numbers. Prices are reasonable and great service. Been doing business with him since '93 with out any problems. 1-888-814-1110.

http://www.delfield.com/docs/uploaded/del/manuals/archive/dm6000.pdf
this is the site with a manual for the 6151S unit.
http://www.delfield.com/docs/uploaded/del/manuals/DM6000XL.pdf
here is another manual for the XL-S unit.
Hope this gets you what you are looking for

Try Rick at Restaurant Parts and More. 1-888-814-1110. They are in Ohio. Have model and serial and he can probably get what ya need.
Hope this helps.

Sounds like a refrigerant restriction in the system. Recover the refrigerant, replace the filter drier and pull a deep vacuum on the system before recgarging.

Check the defrost timer for operation if your unit has one. Some Delfield models have solid state controls. If your system has a timer for the defrost you can open the timer cover and turn the dial in the direction indicated by the arrow until a time peg comes up to the time of day marker. You will hear a loud click and the compressor will shut off. Defrost should take place. The inner dial of the timer will have some indication as to how long in minutes the defrost should take. If the pointer does not move while in the defrost position the timer motor is bad. Turn the dial again so the copper pointer goes past the time of day marker and the compressor should restart. Replace the timer.