Stannah 300?

we have bought a Stannah 300 s/h and was told it was in perfect working order when it was taken down which i believe
When we connected up the charge light came on but it didn't move up or down ,so we left it on charge overnight and drop tested the batteries and they are near perfect
Having downloaded the Manuel it saying unless the green light is on and all the switches are in the right position it wont work switches are on but still no green light on the arm
all the limit switches seem OK and it can be move manually
Any help would be great
Cheers

Stuart Royall
October 2017