GoFlight GF-TQ6 throttles

[Guy]

I have a setup with a B737 yoke and rudder pedals from PFC, and a throttle assembly from GoFlight.
The yoke and rudder pedals work fine but only the throttle for engine 2 works correctly. For the other three engines, moving their throttles makes the calibration value jump suddenly from 1000 to -1000 with nothing in between. I would expect the hardware for all four of them to be the same. As a test I tried these throttles on Xplane, where they operate correctly.
Does anybody have any ideas?
Thanks,
the gie

[Will]

Make sure to set the "Neutral" value correctly. The default is usually 300. Try zero (0) and see what that does.

[Guy]

Thanks Will, I tried playing around with the neutral values but nothing helped.
Then I started Microsoft FSX which has an extensive calibration feature, to see what happened. There also all throttles except throttle 2, as well as the speed brake, behaved more like an all or nothing switch. This was very strange because the throttles worked fine in Xplane where they could readily be calibrated. While trying some things in FSX, including looking at the raw data and possibly restoring to default values, the misbehaving throttles and speedbrake suddenly started to behave as analog parameters and everything is working fine now in PSX too.
I may be wrong but it seems like the handling of throttles in PSX is done via some Windows software to which others like FSX also have access, while Xplane seems to provide its own calibration program.