RE: FP-T7UAF and FP-R127DF compatible?
These should work together. No set-up is required, it should work when the TX is switched on.
I would do some testing with a receiver that is known to be good.
Make sure you have the correct DC crystals.
I would suspect the RX's first, crash damage, it would be a longshot to have 2 bad TX's, but either could be at fault.
Both my T-7's still work fine.