It seems that you have removed all bigger semiconductors from the secondary side of the power supply, so its a good idea to test them.
Get the Datasheet of the component to test, if you are uncertain of how to test a specific part, google and youtube are a good starting point.
Remove all components from the circuit that you want to test, it takes some extra time but it will get you more accurate results.
Check the primariy side as well.
If the Fuse was blown, it may have damaged other parts on the primary side.
Are the switching Transistors BPJs or MOSFETS?
MOSFETS need a different testing approach than BPJs.
Attched is a document that shows the procedure (sorry, it seems as if its available in german only
)
Check the controller chip too.
Desolder the part and check the resistance between VCC and GND.
It should read a high value if the chip is still good, if not replace it and check all surrounding parts too
Most of the cases I've come across were like this:
- Blown Fuse: Problems on the primary side.
- PSU alternating between on and off (restart because of an overload condition) problems on the secondary side (most likely shorted diodes).
Take care of your safety!
- Discharge all Capacitors before you touch anything!
- The big ones on the primary side carry rectified mains voltage, thats about 320V, nothing you would want to get close with!
- Don't short them with a screwdriver, use a 2.2k Resistor with 5W, better 10W to discharge them.
- Check the voltage across them before you handle the PCB.
- Wear protection glasses, components may fail violently, sending out shrapnels.
Regards,
Jens