That is not likely the problem-- it is not getting any voltage thru the transformer and your test just verified it from another direction. you could test it on the board with a current limited power supply, just put 6 volts on the input and should see 5 on the output, but
IC702 (on bottom side) provides the gate drive for the FET, so it is likely not doing it's job. And IC318 (on upper side) provides the feedback signal to ic702, so it will be one or the other of those two chips, or some little passive component in those circuits, resistor, cap, diode, etc. There may be discussion of this on page 9. If i get time i will try to trace it out and draw it up better than the hand sketch, but i have some medical appts tomorrow and will be off line most of the day.
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