Andrew Everard:
You mean you've stripped right back to the yellow, red, blue and black internal insulation? On most cables you'd now cut this away to reveal the cable within, but on very few cables - such as some QEDs - the conductor is actually between the outer cover and the inner coloured core
You need to expose this - there must be metal-to-metal contact between the cable and plug to conduct electricity.
After
stripping back, twist the red and yellow internal metal conductors together and reinsert into the red plug, and the blue and black conductors into the black plug.
Thanks, will do.
Probably ranks among the blonder moments in my life!