| Symptom | Possible Cause | Remedy |
| No LED display on the front panel | 1. Missing battery. | 1. Charge battery up to 8 hours. |
| 2. Battery defect. | 2. Replace with the same type of battery. | |
| 3. Power switch is not pressed at least 5 seconds. | 3. Press and Hold power switch for at least 5 seconds. | |
| Alarm buzzer beeps continuously when AC supply is normal | Overload of the UPS. | Verify that the load matches the UPS capability specified in the specs. |
| When power failure, back-up time is shorten | 1. Overload of the UPS. | 1. Remove some non-critical load. |
| 2. Battery voltage is too low. | 2. Charge battery 8 hours or more. | |
| 3. Battery defect due to high temperature operation environment, or improper operation to battery. | 3. Replace with the same type of battery. | |
| Mains normal but LED is flashing | 1. Fuse is blown. | 1. Replace the same type of fuse. |
| 2. Power cord is loose. | 2. Reconnect the power cord properly. |
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