If you repair SMPS and wish to test it, make sure the load that you are using is big eough for the SMPS. A small load would not turn “On” the SMPS in fact it would cause the SMPS to shut down or even run at a lower voltage (instead of producing 12 volt, the SMPS now only output 7 to 9 volts). If you don’t get the right amount of load to test the SMPS, you might have thought that the SMPS have problem again.
What kind of load do i need to use? Well it depends on what type of SMPS you are repairing. If you are fixing the computer power supply i suggest that you use a motherboard with at least on or two hard disk. You can buy those used motherboards and hard disk from any computer shops. Some power supply only requires a lamp (light bulb) or resistor to work but i do came across some that only will power up with the original load. Hope after reading this post you will make your own decision on what type of loads that you need to use on the Switch Mode Power Supplies.