Normal troubleshooting you will place your black probe to the equipment chassis or cold ground to take voltage measurement. When you do troubleshooting especially on the board where you have removed it from the equipment, make sure you are certain where to place the black probe. The reason i mention this is because sometime a repair tech can get confuse of the grounding. If you place your probe on point A (see the photo above) and measure the output voltage then you will not get any result. You should place your probe on point B which is the cold ground. From the photo, there is a slight confusion between point A and B. So before you start to make any voltage test make sure that you place your black probe on the right point. If you still uncertain which one is the ground, just refer the filter capacitor negative pin and you won’t get wrong.