The sensing fuses in this style of generator have to be removed and tested with a continuity tester. Checking for voltage on the load side of the fuse will not do because if the other sensing fuse is good there will be voltage on both sides of the blown fuse.
After checking the fuses locate the transformer in the center-right of the wiring compartment. It has two separate secondaries. The two terminals toward the rear is one and the two on the front side is the other. Do not disconnect any wires from the transformer. Check for AC volts on each secondary (top), each should read about 18 volts AC. If 18 volts is not present, check the two primary terminals on the bottom of the transformer for 240 Volts ac. If you do have 240, then the transformer is bad. If you do not have 240, then a fuse is blown or there is a wiring problem. It's possible that there is nothing wrong and it is trying to run an exercise. If the green light is not flashing while in Auto and no transfer occurs shortly after it starts, it is probably that. If the green does flash when placed into Auto, then the generator is not seeing utility power (18 volts).
State your problem, not your diagnosis.