Have you checked for continuity through the heating element (as somebody has mentioned above - there's usually a series thermal fuse in-line).
Don't discount the possibility that the wrong components have been fitted at the factory - very easy to mis-read those 51/1M markings (as I did). Try to compare the circuit with those given on the GHD site.
To be honest, unless you see this as a challenge, I would be telling your colleague, with as much authority as I could muster, "Beyond economic repair", irrespective of the truth
Consumer electronics - blargh!