Grumpy_Mike:
When a line is an input it is not exerting any voltage pull in any direction. Doing a digitalWrite() on an input pin turns on an off the 30K internal pull up resistor. This is too high an impedance for some of your servos (your bad ones) but it looks like it is just enough for your other servos, but it is not very good.And I expect the servo controller to initialise the servo correctly
You might expect it but no.
For more on floating inputs, see:-
Inputs
Hmm not sure I understood this, to me I'm using an output which send a pulse of X ms to the servo and not an input.
Maybe it would help me if you tell me between which pin of the servo you advise to put a pull up resistor?
Thanks!