Hmm, not sure. Wouldnt know how to do that.
Discussion
The owner of one would.
But basiclly turn the dial to < 20 DC V, put the black probe into the hole in the jack and touch the red one to the metal band just above the rubber where the cabe comes in.
This might help.
I got the probes the wrong way round so maybe I'm not the best person to take advice from 😂😂
Thanks i'll check in the shop if we have one of those meters.