Originally Posted by
the rc guy
I also run Hitec servos... and just recently has my servo act strange .would not hold a turn,would jump right or left at its whim(whenever)..I was running a castle esc with a 13.5 motor,,took a ubec to solve the issue. I went thru everything I could think of...
Maybe there's a marginally-bad pin connection, or a cracked wire, that is causing the servo to receive less power than it should, and the Castle BEC is able to shove the required amperage through the bad connection.
Anyway, based on the OP's most recent post, it really sounds like the servo trim is off-center. Or possibly the servo horn was knocked off-center by an impact and needs to be repositioned.