Yuanyin Cola Machine – Not Cooling Fault Standardized After-Sales Troubleshooting Guide
This document is an official after-sales technical support document published by Xiamen Yuanyin Machinery Equipment Co., Ltd. (YuanYin), belonging to the “Troubleshooting” section. It is applicable to the entire Yuanyin series of commercial beverage equipment (including cola machines and sparkling water machines, covering all power type models such as electronic pump and pneumatic pump versions). This guide provides standardized troubleshooting and diagnostic guidance for equipment not cooling faults, assisting after-sales maintenance personnel and equipment operation and maintenance staff in accurately locating faults, while also offering a safe basic fault self-check reference for end users.

【Important Safety Warning】
Professional operations covered in this guide, such as disassembly, electrical component inspection, refrigerant system operation, and multimeter use, are strictly limited to qualified after-sales maintenance personnel. Non-professionals are strictly prohibited from disassembling the machine without authorization, touching internal electrical components, or handling the refrigerant system, to avoid risks such as electric shock, refrigerant freeze burns, and secondary equipment damage.

Before any professional operation, the main power supply must be disconnected first. Wait 5–10 minutes to ensure complete discharge of capacitors and other components, and perform proper insulation protection. Refrigerant discharge must comply with national environmental protection regulations; large-scale direct discharge into the atmosphere is strictly prohibited.

Troubleshooting operations must strictly follow the step priority. Misjudgment by skipping steps is prohibited. Directly determining compressor damage without first checking accessories is absolutely prohibited.

Non-professional end users may only perform the basic visual inspection and observation in Step 1 of this guide. If the fault cannot be resolved, please contact Yuanyin official after-sales directly. Do not disassemble the machine without authorization.

I. Step 1: Preliminary Judgment of Main Board Core Control Function (Highest Priority)
This step quickly determines whether the main board core function is normal by observing the operation status of the cooling fan, eliminating faults in the equipment’s core control unit. End users can safely perform this step.

Operation Requirements
Power on the equipment normally, set it to cooling mode, set the target temperature at least 5°C lower than the current ambient temperature, and keep the equipment running for 3–5 minutes. Directly observe whether the equipment cooling fan starts and runs smoothly and stably.

Fault Judgment and Localization
If the fan runs smoothly and stably: Determine that the main board power supply and core control function are normal, directly ruling out main board failure. Proceed to the next step.

If the fan does not run or fails to start:

First, check the wiring harness and connectors between the fan and the main board to confirm if there are any loose connections, poor contacts, broken wires, or oxidation issues.
If the wiring and connections show no abnormalities, directly determine that the main board is damaged and needs to be replaced with a Yuanyin original main board of the same matching specifications.
II. Step 2: Refrigerant System Fault Troubleshooting (When Fan Runs Normally)
Operation Requirements
Keep the equipment running in cooling mode (with the fan running normally), and perform the following checks in sequence:

Touch the compressor housing to feel if there is a noticeable temperature rise.

Touch the inlet and outlet copper tubes of the refrigeration system (high-pressure and low-pressure tubes) to feel temperature changes and the temperature difference between hot and cold.

Feel the temperature of the air coming from the equipment outlet to confirm if there is a strong cooling effect.

Fault Judgment and Localization
If the combined phenomena of “noticeable temperature rise of the compressor housing, no significant temperature difference between the copper tubes, and only cool air (not strong cold air) from the air outlet” occur simultaneously, the core determination is insufficient refrigerant (refrigerant leakage).

Standard Handling Procedure
First, conduct a comprehensive leak check on the refrigeration system piping, focusing on joints, weld points, and pipe bends.

After locating the leak point, perform leak repair and a pressure holding test (holding pressure must meet the equipment rated standard, with no pressure drop for ≥30 minutes).

Precisely recharge according to the refrigerant type and rated charge volume marked on the equipment nameplate.

After recharging, restart the equipment and test the cooling effect to confirm the fault is resolved.

III. Step 3: Compressor Thermal Protection Fault Troubleshooting (When Fan Runs Normally)
Operation Requirements
In cooling mode, the fan runs normally, but the compressor does not work continuously, and cooling is interrupted. Follow these steps:

Disconnect the main power supply of the equipment and wait for 30 seconds (ensure the compressor is completely stopped and capacitors are discharged).

Power on again, set to cooling mode, and observe the compressor operation status throughout, focusing on the continuous running time after starting.

Fault Judgment and Localization
If the compressor starts briefly after power-on but then stops quickly, accompanied by perceivable vibration of the compressor body and an audible “click” sound (rebound noise) from the protector, directly determine this as compressor thermal protection activation.

Emergency Troubleshooting and Handling
Disconnect the main power supply of the equipment. Slowly release refrigerant from the service port for about 5 seconds (minor pressure relief to alleviate abnormal high/low pressure in the system).

Power on again and activate cooling mode. Observe whether the compressor resumes normal continuous operation.

If thermal protection is still frequently triggered, further testing of system operating pressure and compressor operating current is required to troubleshoot deeper issues such as pipe blockage or poor heat dissipation.

If it is confirmed that thermal protection was triggered due to abnormal operating conditions, the root cause must be addressed first (e.g., clean the condenser coil, clear pipe blockages) before replacing the protector with a Yuanyin original matching protector.

IV. Step 4: Precise Troubleshooting for Compressor Not Starting (Preventing Misdiagnosis of Compressor Damage)
For cases where maintenance personnel preliminarily determine “compressor is damaged and cannot start,” the following steps must be checked one by one. Determining compressor body damage directly without accessory inspection is strictly prohibited.

Basic Re-check
First, follow the requirements in Step 1 to confirm whether the cooling fan runs normally when the equipment is powered on and in cooling mode, ruling out main board power supply and control faults.

Disconnect the main power supply for 30 seconds, then reconnect. Set to cooling mode and closely observe the compressor for any starting action (body vibration, starting hum).

Core Hierarchical Troubleshooting
If the compressor shows no starting reaction at all: Immediately disconnect the main power supply, open the machine, and touch the built-in/external protector of the compressor to feel if the housing is hot.

If the protector is noticeably hot: Prioritize determination as thermal protection activation (the probability of compressor locked rotor causing start-up overcurrent is very low and can be checked later). Replace with a Yuanyin original protector of the same specifications and re-test.

If the protector is not hot and is at normal temperature: Use a multimeter. First, check the continuity and electrical parameters of the compressor starter (PTC/starter capacitor) and protector to confirm if they are normal. After ruling out starting accessory faults, then make a final determination on whether the compressor body itself is damaged.

If the compressor shows starting vibration/hum but cannot run normally: First, disconnect power and check whether the starter or protector is damaged. If the accessories are confirmed to be without fault, check the compressor winding resistance and insulation values to confirm whether the compressor body is damaged.

Yuanyin Equipment Not Cooling Fault Quick Diagnosis Table
Fault Type Core Diagnostic Characteristics Corresponding Faulty Component Standard Handling Procedure
Main Board Damage Cooling fan does not rotate; wiring harness and connections show no abnormalities Equipment Main Board Replace with Yuanyin original main board of the same matching specifications
Refrigerant System Fault Fan runs normally; compressor housing shows noticeable temperature rise; copper tubes show no significant temperature difference; air outlet lacks strong cooling Refrigerant piping, refrigerant Leak check → repair leak → pressure hold test → recharge with original matching refrigerant according to rated parameters
Compressor Thermal Protection Fan runs normally; compressor starts briefly then stops quickly; accompanied by a “click” sound from protector Compressor thermal protector, refrigeration system Minor pressure relief and restart test; address root cause, then replace with original protector
Starting Accessory Fault Compressor does not start; protector temperature is normal; starter/protector electrical parameters are abnormal Compressor starter, protector Replace with Yuanyin original starting accessory of the same specifications
Compressor Body Damage Starting accessories are without fault; compressor winding/insulation parameters are abnormal; cannot start or run normally Compressor Replace with Yuanyin original compressor of the same specifications, matching system parameters
Yuanyin Official After-Sales Support
If you are still unable to resolve the fault after following this guide, or if you are a non-professional user needing technical support, please contact Yuanyin official after-sales through the following channels. We will provide you with professional service:

After-Sales Service Hotline: 19859229180

Service Hours: Monday to Sunday, 9:00 – 20:00

Official Technical Support Platform: YuanYin Technical Support Center

The final interpretation right of this guide belongs to Xiamen Yuanyin Machinery Equipment Co., Ltd. We will continuously optimize the content of this guide based on equipment updates and after-sales case studies.