I ALWAYS, ALWAYS, ALWAYS cycle (break-in, burn-in) new servos for at least 30 minutes using an old ACE Servo Cycler. Have found a few over the years that went belly-up during the burn-in.

I ALWAYS, ALWAYS, ALWAYS fly a new receiver, or one that has been in for repair or checkup, in a bird I keep just for that purpose. Also check out the transmitter after repair or checkup the same way. Have found some bad crystals and one bad receiver this way.

Call me overly cautious, paranoid, or whatever but I have never lost a plane to a servo or receiver problem. Dumb thumbs usually does them in...

(Edited due to being a lousy speller......)