Same Machine I have a Freeze Bee machine that looks like the your 501 - would they be the same machine? The mixing gears and controls look the same. Manufacture date 2-18-93. The unit I am looking at has the following specs: SaniServ 11 Qt 2-flavor Twist - 435 lbs, 24x32x33.

a few potential causes and solutions you can explore:

Low Mix Level:
Problem: The MIX OUT light is on, indicating that the mix level is low.
Remedy: Add more mix to the mix hopper and return the machine to AUTO mode.
Power Switch Position:
Problem: The power switch might be in the OFF position.
Remedy: Ensure that the power switch is set to ON and select AUTO mode.
Machine Not in AUTO Mode:
Problem: The machine might not be in AUTO mode.
Remedy: Select AUTO mode and allow the machine to cycle off before drawing product.
Beater Motor Reset:
Problem: The beater motor might be out of reset, and the BEATER OVERLOAD message is displayed.
Remedy: Turn the machine off, press the reset button, and restart it in AUTO mode.
Freeze-Up or Blockage:
Problem: There could be a freeze-up in the mix inlet hole or an issue with the feed tube.
Remedy: Call an authorized service technician to address the issu

Try contacting the vendor to ask for a manual.

https://jmbeiqi.en.made-in-china.com/product/UbrEcLGTvHkN/China-Soft-Ice-Cream-Machine-BQ323T.html


Hot Item Soft Ice Cream Machine BQ323T

I am assuming that it is the left side that is freezing up? Is there a large disparity in temperature from the left side to the right? Your machine monitors the temperature on the right side hopper and that will determine the temp of both sides. If there is a large temperature difference between the two sides then it may be that you are low on refrigerant. You may have enough refrigerant to cool the left side but not the right side and since the machine only monitors the right side, it wont shut off the mix refrigeration system which could cause the left side to freeze up.

Viscosity adjustments should not have to be made frequently on these machines. If you change products a lot, such as flavors of yogurt, minor adjustments may be required. If your machine uses 3 phase electricity and it machine has been moved or any electrical work performed you may want to check the beater rotation, the beater should rotate clockwise inside the barrel viewing from the front, if you look at the gear box from the back, the pulley should be turning clockwise as well. Otherwise, there is a fine tuning potentiometer on the control, you must remove the front cover to see it. Clockwise is colder/thicker. I recommend small adjustments. It is best to read the amp draw on the motor to see what type of amps it is drawing. If your mix is soft and your motor is drawing 4 amps, you may have another type of problem such as a bad motor. The board and control can also fail giving these problems. There are many things to check in addition to these. Hope this will help you get started.

My small Business had this same problem. The first thing you need to look at is the product you are using. It turns out that if you are making your own soft serve. which Includes water and powder, it will save you a lot of time and stress to switch to cartons of soft serve that you just pour right in. It turns out that there is no consistency in powder icecream. the water will eventually separate from the mix, resulting in watery soft serve once dispensed from the machine. Next, if this isn't the prduct you are using then it can be other problems such as your compressor not working, or turning on when it's suppose to, maybe you have a weak motor, or your machine isn't set to the proper freeze level, Also, make sure that your machine isn't backed up against a wall or I between two other machines. These machines need to Obsorb cool air in order to work properly and not overheat . The machine's fan, which is located on the right side, needs to be have a certain amount Of space from walls or other machines. If this doesnt work you can always call a technition to come and check out the machine, I hope this helped, best wishes with your repair

a.improper pressure switch setting . b. low refrigerant level. c. TQC needs adjusting. d. faulty solenoid. e.insufficient mix in freezing cylinder.

Welcome to FixYa
An electric ice-cream maker is a tabletop appliance for mixing and freezing ice cream at home. A small electric motor drives gears that turn the canister filled with the ingredients for ice cream. The canister is surrounded with ice and rock salt to freeze the contents. Alternately, a hand crank on top replaces the motor.
Although durable, ice-cream makers can require a few repairs. A common problem is damage to motors or gears from mixing too large batches of ice cream or from neglecting a jammed mixing paddle. The electrical cord can fail and motor bearings can dry out.
Read Following ...

• Use your cylinder bowl correctly. If the cylinder isn't handled properly, your ice cream won't set. Make sure it is dried completely after washing so ice doesn't form on the walls, make sure to leave it in the freezer overnight before making ice cream and don't leave the bowl out at room temperature before using.
• Check your freezer door. If it isn't sealed properly, or if it's constantly being opened during the freezing process, your ice cream can't set properly.
• Handle the ingredients correctly. Don't let the ingredients warm and don't overfill the bowl. Check the manufacturers recommendations for the maximum bowl capacity.
• Clean and dry your machine thoroughly. Use a damp cloth on the motor assembly; never immerse. Make sure to wash the lid, blade and cylinder according to directions and make sure the cylinder is absolutely dry before freezing.
• Contact the manufacturer's support site only after you have exhausted your options. They may walk you back through the steps you've already taken, but at best your problem will get fixed far more quickly because you eliminated the easy problems in advance.

I hope this Instruction guide will help you Click here Read carefully Instructions[Specifically Page27, 29,31]
OR click here
Just Check this Link too
Thanks for Contacting FixYa...

Check and see if all of the wires are on the freeze/cleanout switch. make sure the switch is in the freeze position. There is also a torque switch in back of the unit where the belt is,the belt tensioner engages and disengages this switch to control the viscosity of the mix in the barrel.check to make sure the metal arm of the switch hasnt been bent so far that it will not move, and that it does not have mix in it. Also check the voltage to the contactor coil. if you have correct voltage at the coil, then it is a bad contactor.

Couldn't find a manual for you.
But i found a link to SaniServ to contact them for techincal support:
http://www.saniserv.com/contact.jsp?p_=&go=no&form=4

Hopefully they can tell you how to fix your machine.
Good Luck