what I'v knowticed is...
spek RX+ jr 650 servo = RX low volt shutdown
spek RX + 617 bluebird servo= same thing...
BUT!! I'm starting to think that the MMp killed one of my spek RXs, it(RX) worked fine on thu when I used my RX8, but when I switched to the MMp it started to shut down and glitch
this was in a t4, 2s, 6.5
also the esc hit 120-130 with the fan not turning on...