Minnie Winnie 22r GFI not working

[Rupp825]

We have newly purchased 2017 MW 22R and the GFI is dead will not reset. I checked all of breaker switches reset them, checked all the fuses - good, then purchased a new GFI and installed it and still no luck. What do I try next.
Repair shop says next appointment is later in August and very expensive to debug and fix.

[Goodspike]

This would be stupid, but is there another GFCI outlet in the unit that might be daisy-chained in ahead of this GFCI outlet?

If not, what I would do it test each of the 120 volt outlets and see which do have power. It's possible a connection came loose on one of them ahead of the GFCI. But if it's every outlet not working that would push you toward needing to look at the breaker box.

[Goodspike]

Assuming the microwave is on a separate circuit, I would check it too.

[Morich]

There are two versions of your year, early and late, so I choice early but both appear to have the same circuit on this item and it is quite simple as the GFCI come nearly straight off the load center. I've marked in green the breaker, but some basic will help sort it. One is the leftmost 30 amp breaker feeds all the other breakers in this box, so check something simple like the microwave for lights and that will tell you the power is getting to the load center box and almost certainly to the first 15 amp breaker from the left which feeds the GFCI.
If I am correct on the right drawing (check me, always!) make sure the 15 amp is working if you get lights on the micro. Try flipping it off and back to make sure as they can appear good when flipped. If that is good, power should be going straight to the GFCI, if not there is a loose wire at the breaker or GFCI, or a bad breaker or GFCI or one other. Checking for a good connection on the ground as well as the hot side is always good.
But be aware that GFCI trip when there is a "ground fault" meaning power is leaking to ground where it should not. It could be right at the GFCI or on the wiring to the exterior or bath outlets, so give a look at each of them. Not wet are they? One first stop test might be to take the wires going from the GFCI to the others off and see if it will reset, telling you the problem is on to the other outlets.
Also keep in mind to check the wiring on the GFCI for "human failures" as they do happen to the best of us. Make sure the load and line is turned the right way? And it is always possible to get a defective new one.
Drawing does not cut and copy very well so this is the original if you can access it on page four:
https://www.winnebagoind.com/diagram/2016/000200769.pdf

[Rupp825]

Now I know what to test next, much appreciated.

[Rupp825]

I solved the problem by switching the wires around on the GFI...
The blue circuit came from the top 15 amp breaker and went to the top two input ports on the GFI, then the bottom two ports on GFI went down to External plugs outside the door of coach, then lastly to the bath plugs. I found that only the top plug of GFI had live power and the bottom plug of GFI was dead. So I decided to try switching the two inputs on GFI, moved the top two wires on GFI to the bottom and moved the bottom two wires to the top of GFI. Now all plugs on blue circuit WORK!!! Both plugs on GFI, external plugs and bath plugs all are live and working.
So it is important to be sure the blue circuit from breaker box goes to the BOTTOM inputs on GFI.
Thanks for all the input from Goodspike and Morich.
Phil