Hi Jim.
I have got another 17pw26-3 with the FAN7711 on it the fets are not s/c'd but out of circuit they do give strange readings I have found the fets and ic for a tenner on flebay so going to get them.
Thanks for the readings...I am going to go with new to be sure
Valves...didnt they power the arc...saying that though I was looking at a valve amp recently in a specialist stereo store...looked the business, sounded the business....just crapped a brick at the price, with hyperactive kids, wii remotes and sticky up lighty things popping out the top of an amp do not mix...I can even hear that distinct popping noise now...followed by that distinct noise of "It wasnt me"