tac 50 fault 813 & 690

I have a tac 50 elevator that takes itself
out of service on the bottom
terminal level producing 813 & 690 faults.
It also faults the DSP board out and red solid red light stays on.

Only way to get it to reset is
to power down then power back up then run car to next floor up on insp service.

Then it can stay in service for as little as the next day or as long as 3 weeks.

Has anyone else have had this problem?

690 Motor Encoder Fault A run was requested but no motor feedback was detected. The delay between the run request and the fault occuring is set with SCN. Improper brake adjustment. Improper feedback delay. is it the first run of the day when it occurs. 813 Negative Torque Limit error, The torque command signal tried to exceed the negative torque limit value. Sounds like brake to me. Or noise on encoder wiring. 5vdc power supply low?