Carlton Ultrablend Help

I’m looking for help operating a used Carlton Ultrablend machine. It powers up, but does not seem to leave standby mode, even after I insert the needle, while holding the indifferent electrode in the opposite hand, and press the button on the (switchable) needle holder (which should complete the circuit). Not sure if the machine is DOA or if I am missing something here.

A test I found useful after purchasing a used Sterex sx-b was the bubble test.

Josefa posted a video here:

You can also try the egg white test:

My issue ended up being the needle holder. I needed a replacement.

Thanks, mh.