The resistor I had trouble with is R13, visible in the second picture, left board, between D2 and R12. R12 is another important resistor and can be checked from the other side of the board.
Check none of the voltage regulators are getting overly hot. U401 takes the raw +24v and produces 6.7v which then feeds U402 to make the +5v digital supply. When the 9v is there it 'takes over' from U401 which effectively turns off. From your pictures U401 has no heatsinking, whereas U402 does. 401 is dropping maybe 15v, so should be dissipating many times the power of 402 and they thought it worth bolting 402 to the chassis.I have been using it all night and it sounds fantastic, I have ordered up a 9v toroidal transformer to try and squeeze into the unit but after testing all functions and having a good listen I really don’t see the point in fitting it.