kds 800 gyro dead?

[Dutchdrifting]

So my brother has bought a second hand kds 450s wich has a kds 800 tail gyro and a n590 tail servo. Last week he has tested it and the gyro and rudder response worked.

Today I wanted to help him out with setting up the heli for his first flight and the tail servo is no longer responding to rudder inputs. As soon as I plug in the lipo, the tail goes full left and stays there.
The rudder endpoints where set to far on the gyro. Turned them down to 60%

What I have done so far to try and solve the problem.
I have set the gyro to digital servo. As it is a digital tailservo.
I have set the delay to zero, as the manual stated to use for digital servo's.
I have tried the tail servo on the pitch channel. It works as should.
I have tried the digital pitch servo on the gyro and just as the tailservo, it goes to full left straight away and doesn't respond to rudder inputs.
The travel limits have been set to the lowest setting possible to be safe.
the led on the gyro is constantly on and with rudder input it starts to double flash. As it is supposed to do according to the manual.


As I am not used to tail gyro's, I have only flown fbl heli's, I could really use some help on this problem.

Thanks very much
Youri