servo has limited range


i have two servos, JX PDI-2506MG, that can only be driven between ~45° and ~135°
makes a rapid clicking when attempting to drive past these values.(guess: motor is oscillating to hold position)
mechanically it is capable of doing ~0° to ~180°.

i'm testing with the stock sweep sketch,it is producing the correct timings.(confirmed by scope)

a known servo,a JX 6632MG, in parallel works as expected.

internal pot appears to give approximately correct values for various angles.

any ideas?

The specification says that's a programmable servo. So I guess it's been programmed for only +/- 45 degrees. Unfortunately since I've never seen one of those servos I don't know how you go about reprogramming it.


thanks Steve.

dump for future reference:

the servo uses a KC9806 ic which is programmable
however the datasheet makes no mention to the protocol.

it is supposed to be programmable using a EMAX configuration card, according to

datasheet attached

kc9806E.pdf (175 KB)