if you have no 120v power, and:
A) the shore power breaker is not tripped
B) your internal Main breaker(s) are not tripped
C) your generator's own breaker is not tripped
then, you have an issue BETWEEN your ATS, and/or Shore Power cord...
the ATS(automatic transfer switch)'s job is to sense power and allow it to come into the coach, BUT it also will determine 'which' 120v power is to be used, if two are available at the same time.
IF you crank your generator, and it's breaker is not tripped, your ATS will use the generator power, EVEN if you have shore power.
If you don't have generator power, then it will look to use Shore Power, IF the shore power is available.
If the ATS is not operating properly, it could 'delatch' and not provide a flow of 120v power, even if the shore power or generator is working properly.
Many people have had issues with LOOSE wires within the ATS. It's a box, with incoming Shore and Generator power lines, and an outgoing line to your Breaker box. Check and see that ALL wires are TIGHT.(while NOT plugged in or the generator running, of course)
If that is not the issue, then your Shore Power CORD could be the culprit, as they also sometimes loose their connection with the power, either at the side that's connected to the RV, or the end that is plugged into the Shore Power.
If you have a 50amp shore cord, and are using a 30amp adapter, it ALSO could be the issue. Try plugging into another Shore Power pole outlet, or try another adapter.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
110,000+mi since '14 - US, Alaska, Canada (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )b