I have had 2 Nomad IIs. First one lasted 6 months. Second one is still working fine. Had it since July 2019. What I did do was get one of the Hill EC 3000 units just before Christmas and now it is my primary unit. The Nomad II is for "field trips" and as a backup.
Looks like you got a couple options, send it back for repairs or try fixing it your self. Below is some info/research that may help you figure out what is wrong and
which direction you want to go.
I personally have already decided that
WHEN my Nomad II goes out I
WILL tear into it. If you decide not to send yours back for repair then it is just a paper weight and you have little to lose by working on it yourself.
Top two references are for the Hill EC 3000 but show simple problem of not building up air pressure and simple fixes.
This one is from the BLUE COLLAR SPORTSMAN channel.
https://www.youtube.com/watch?v=nPZQIYVdAwo
This is one is direct from Hill.
https://www.youtube.com/watch?v=pIJ49y0_eFc&t=3s
Here are a couple from this forum.
"AG Nation forums Nov 23, 2019 at 9:44pm titled: Air Tanks, Pumps, Compressors, & Filters › Unbranded Spark mods"
and
https://www.airgunnation.com/topic/tuxing-txet061-2/ Here is a schematic and parts available from Pyramid Air. They also have USED parts available that they salvage from non working units.
https://www.pyramydair.com/model-schematic/a/air-venturi-nomad-ii-4500-psi-portable-pcp-compressor/8695#8587 This one has a lot of good info (except for the dumb music).
https://www.youtube.com/watch?v=CVjPaOQ_jR8&t=472s
This one is kinda long winded but very good from BROTHERS IN AIR. It may help you understand what is going on and how to fix.
https://www.youtube.com/watch?v=SnRqLhLEQ2E
Too bad Air Ventura
doesn't care enough about it
customers and its products to produce repair manuals and videos. But I must say I have had nothing but great communications with their tech people. They are top notch.
Sounds like you may be a young wiper-snapper. My advice is the sooner you
buy tools and dig into things like this the longer you have to use them and to perfect your skills. You can always tell the misses some nut on the internet talked you into it. HAHA
Congrads on the upcoming marriage.