I managed to get some free time today to test it. I don't get it but it defenetly needs the 12V power. I tried the 5V but the board was unresponsive. I'll try sharing an image laterSomething doesn't smell right. If the VCC and +5v pins have continuity then VCC isn't +12v. I'm pretty sure you only want +5v. The relays are 5v, not good if you put 12v to them. If the 5v supply isn't enough power it's due to lack of current available. Each relay draws 60 - 80 mA so lets say 100mA x 16 relays = 1.6 amps required to activate all relays at same time. If you get a 2-3 amp 5v power supply you should be set.