Hi most odd, as most the chips are running on 3V3 and 5V and are down stream of the regulators IC2 and IC1. IC 3 and 4, which form the receive chain, runs off VCC, which is 5V, check you do have 5V. The AMS117 has had issues. I can not see where IC5 gets its supply from, I presume it is from VCC. My unit happily ran up to 13.8, but the power was too high 6-7 Watts, so I rewound T1 for 9V operation and I get 4 Watts according to my bird wattmeter with a 50W element.
The AMS117 has had issues,
Good luck lets us all know how you get on.
73
Andrew
Andrew Lenton