So, Im helping the neighbor kid with his b6 club racer and I can not get the 600z esc to calibrate. Anyone have issues with the 600?

It does fine until I try to calibrate full reverse/brake. Instead of saving the setting, It starts flashing the red led.. Im out of ideas. Ive tried 2 different radio systems.

Ive been racing since the late 90's, so I know what Im doing. But maybe Im overlooking something? I plan to call AE tomorrow if I cant figure it out today.

Thanks!