mx400 collective pitch servo pinned itself down...HELP

[Spectre]

My MX400 (x400)'s Collective pitch servo pinned itself in the down position when batt. is connected. I have tried to reverse it and it still does the same thing. I have tried trim and it still does it (no movement).
I move the throttle and the collective pitch servo does not move at all.

I unplug batt. Center the servo arm and plug batt back in and the servo arm slams back down to the down position.

any thoughts?

Thanks in advance.

Spectre

[jrohland]

Take the servo horn (arm) off and see if the servo works. If it does, center the left stick and put the horn back on in the center position. If not, think about replacing/repairing the servo. Of course, I assume the radio is not fouled up.

There are several things that could cause this:

The horn slipped. Not likely but, possible.

The gears inside the servo slipped. Possible and, if so, the gears are probably damaged.

The positional potentiometer shaft slipped out of place. I've had that happen when the friction fit got loose.

In most cases, the servo is probably damaged. They are pretty easy to repair as long as you can get parts for them.

Good luck,
jrohland

[Spectre]

thanks jrohland,

I will try this all tonight.


it might be the tx too because, that servo is getting the signal to go to that position but, when I do move the th stick I get no response from the servo.

~Spectre

[Spectre]

The gears are stripped out on the servo. I have not even flown the heli yet :(