Colchester Combi 4000 (1998)

[gollame]

Hi, we have an alarm error it reads "1000 spindle monitoring error 17" then straight after, we get on both axis the 401 servo alarm VRDY off error. Basically if the spindle goes over 50 rpm it cuts out, stops and these errors come up, we press reset and after some time its ok and ready to go again but wont go over 50rpm. Now on this machine there is an option called the combi mode, a user friendly software control, using the combi mode we can turn her over at any desired speed which is strange, The control is Fanuc 210i-T so given these circumstances it must be something stupid...? have checked all door locks, theres only one and all appears ok. Can any one shed any light on it, hopefully soon as i'm already way behind on this work and its just typical its a new customer...!!!
thanks in advance
Calvin
ps i don't no how to programme the combi side of it.

[gollame]

thanks for all your help...! ive fixed it, turned out to be a sticky door limit switch on the solenoid.