Here is one thought that I have not see posted about your 120 volt power supply.
My coach is 12 years old with about 115,000 miles on the clock. After a time I have noticed that the ''screws'' that hold the wires in the breakers will get slightly loose. I think this is caused by the bouncing of the coach on the road and the wires/ breakers heating up in use and cooling off when not in use.
With that In mind ,,,,,, here is what I do....
one...... I unplug my coach from the 120 source plug in.
two..... I take the wires off the batteries that feed my 12 volt system.
three..... I double check everything to be sure I HAVE NO POWER FEEDING THE ELECTRICAL PANNEL.
four....... I take the front off the electrical panel after removing all the business cards, phone numbers, pictures, reminders and other misc. stuff that gets stuck on the front of the electrical box.
five..... Standing on a piece of dry plywood, I reach inside with a flat blade screw driver and tighten the bolt/screw thingie on the end of each breaker where the wires are stuffed in.
five A... You would be amazed that sometimes I have turned the bolt/screw ''thingie'' as much as a ''half turn'' to get them tight.
(note***** You do not have to be Sampson too turn these bolts. Just apply steady pressure while turning and ''feel'' for movement.....DO NOT STRIP THE THREADS)
six.... look at all the wires coming into the breakers. Look for Burnt wires and corroded wires. Use a good flashlight and check them out carerfully.
seven..... Be sure that the ''inside'' of the breaker is pressed down firmly on the ''bus bar'' inside the box. Just take your finger and press on the ''inside of the breaker'' to feel for movement.
eight. While you have the front of the electrical panel open give everything a good ''look a round'' inside it. Look for dead rats, spider webs, mud dobber nests and anything that should not be in there and sweep it out of the box.
Nine. Put the cover back on the box. replace all the pictures, notes, business cards and all the other stuff you had taped to the front. Go outside and re hook your batteries and plug the cord back into 120 power box.
ten....... Go inside and test everything on 120 volts. If it all works yell ''YEEEEE HAAAA WWWW AAA'' and get a beer and flop on the sofa and celebrate.
Remember this ......... All this advise is free and you are free to use it or not..... YOUR DECISION.....
When you see a military person, give them a warm handshake and a big hug and say THANK YOU FOR YOUR SERVICE... They like that .......cj...