| Fault content | Cause of occurrence | Take actions |
|
Module can not normally start |
1. Output external capacitive load is too heavy; 2 .Input power is not enough; 3. Output of the load is too heavy or start current of back-end load too large 4. For YAWN series module(open frame), not according to the technical manual required to external capacitance. |
1. Value of the external output capacitance don’t more than the capacitive load specified of technical manual; 2. Increase the power of the input; 3. Choose to a higher power supply module, or reduce the output load; 4. Refer to the technical manual parameters for external capacitors. |
|
Module start transient failure |
1 .At the start exist surge current; 2. Output of the load is too heavy or start current of back-end load too large 3 Input voltage is too high |
1.Use recommended protection circuit in the front of the module plus surge suppression circuit; 2. Choose to a higher power supply module, or reduce the output load; 3. Reduce the input voltage to meet technical manual requirements |
|
Output voltage too low |
1. Power shortage of input ; 2. Output load (including capacitive load and inductive load) is too heavy; 3. Load and module output lead loss is too large. |
1. increase the power of the input power; 2 .Choose to a higher power supply module or reduce the output load (including capacitive load and inductive load); 3. reduce load and module output lead impedance. |
|
No-output |
1. Output terminal external load short circuit; 2. Input terminal external fuse is broken or PTC thermistor overheating; 3. Input voltage does not meet the requirements of specifications. |
1. Check whether the output pin is welding error; 2. Check the fuse and PTC thermal resistance value whether too small; 3 Check if the input voltage is in the range of technical specifications. |
|
Output ripple noise too large |
1. Output external connect filter measures is not reasonable; 2. The oscilloscope is not reliable grounding; 3. Bandwidth selection of the oscilloscope is not consistent. |
1.recommended filter circuit of reference manual to external connect filtering measures; 2. Check the grounding of the oscilloscope whether good; 3. in the general product, the general choice of oscilloscope bandwidth noise test is 20MHz. |
|
Easily damaged |
1. Input voltage is too high or low; 2.Working temperature is too high; 3. Output load is too heavy. |
1 .Input voltage is strictly controlled within the operating voltage range; 2. At high operating temperature, need to derating used (According to the power drop curve of the temperature range and technical manual to use); 3 . Choose to a higher power supply module or reduce the output load. |
| Triple output, which is positive voltage output accurate, but± output voltage is too low |
1.Single positive voltage output is no-load; 2.Single positive voltage output terminal load is too light, ±Voltage output load is too heavy. |
1.Chang to dualoutput of the AC/DC or positive voltage output plus false load; 2. Select smaller output power AC/DC or positive voltage output plus false load. |
|
±dual output power module, positive voltage is low and negative voltage is higher |
±output of the load is not balanced, voltage of heavy load is lower than light load. |
1.Add false load,at light load side, (not more than 2 times); 2.Choose single output AC/DC plus ±dual output DC/DC, DC/DC provides balanced load. |
| After working a period of time, ripple of output is increased and not normal load | Operating temperature is too high. |
1.Installation position should be far away from the high power heating element; 2.use heat dissipation measures, reducing the working temperature; 3. At high operating temperature, need to derating used (According to the power drop curve of the temperature range and technical manual to use); |
| Mutual interference with customer system or not meet the EMC requirements |
1.too close to the system sensitive device; 2.Not in accordance with the technical manual external connect EMC circuit. |
1 Adjust the distance between the module and the sensitive device, and take the shielding measures; 2 According with recommended of the technical manual to use EMC protection circuit. |
|
Exist noise, after electrify |
1.Module is in the light load state; 2. Impedance of the the back end load of module is not matched with the impedance of module. |
1.Advise that load back-end of module is connected to at least 10% load, If the noise does not affect the normal use, the customers can rest assured to continue to use. 2. Recommends that customers according to the actual application situation in the module back-end external capacitors for debugging. |
| After working a period of time, Output short circuit | The back- end of the module has the reverse voltage (such as relay and other inductive devices) | Recommended for customers to add diode and TVS tube at the back -end of the module |
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