Micro Maestro 6 channel USB sevo controller

Have used this controller many times before and use 12v dc to power brd. Just recieved new controller and your basic 2 channel SPDT relay carrier with 12v relays model # 2487.

Everything works fine with usb connected to computer 12v powering brd and relays.

When i disconnect from computer the relay board rattles like a short.

If i use a 9v battery to power board it works fine not connected to computer.

I thought you can use up to 16 v to power board and i have used 12v many times before.

Any info would be great

Hello, Bobby.

The Maestro servo controllers have an operating voltage range of 5V to 16V, so a 12V power supply should be fine. Can you post some pictures of your setup that show how everything is connected? A wiring diagram might be helpful too.