Symptom: the DC output of the power supply is very low with fluctuating and ticking sound from the main transformer.
This can be due to:
1) shorted load/too much current draw by the load.
2) Bad start-up/running cap of the power supply generated by the AUX winding of the main transformer.
3) Bad SMPS IC.
After removing the loads, check the rectifier Diode, start-up cap verification of the ESR and value, DC filter cap, MOSFET, etc.
Last component checked was the Snubber Diode (P6KE150A, 128V 600 Watt Transient Voltage Suppressors) for the MOSFET, it reads 50 Ohms on both direction.
This can be due to:
1) shorted load/too much current draw by the load.
2) Bad start-up/running cap of the power supply generated by the AUX winding of the main transformer.
3) Bad SMPS IC.
After removing the loads, check the rectifier Diode, start-up cap verification of the ESR and value, DC filter cap, MOSFET, etc.
Last component checked was the Snubber Diode (P6KE150A, 128V 600 Watt Transient Voltage Suppressors) for the MOSFET, it reads 50 Ohms on both direction.
Attached Files