The easiest thing to do IMO is try starting the machine without buckling seat belt. If it starts, service/run is in service. Flip the switch the other way and try to start it. If it starts then something is wrong with switch or wiring causing machine to be in service mode. If it doesn't start, service/run is likely working properly and thus the issue is further down the line. 

With the older display you could run a diagnostics test through the display to see if everything was working right but I know the newer ones had far less features.

Attached is the wiring for the service/run switch on the earlier LS machines.





 

(service_run.png)

service_run.png (142KB - 971 downloads)