Genuine problems are fairly rare, but unfortunately there are a few "features" which can cause problems.

No beam 

Is the front end open? Is the safety shutter open? Should the monochromator feedback running? Is the undulator gap in the correct position, sometimes it is opened but not closed again after a refill...  

Software problems

If spec hangs try control-c followed by reconfig. If spec is behaving in a strange way: try the reconfig command. If some windows based software (eg: imagepro or smart) has crashed and will not restart then try rebooting the PC. When restarting these programs, do not forget the device server (bar code icon on the desktop), and of course, reconfig in spec.

Safety Interlocks

All hutches must be properly searched and locked before the beam can be delivered. The EHO (ext. 2525) can usually assist if you have problems. Various programs are available from the unix machine id11 to assist with monitoring the state of the beamline. The id_appli program gives details about the front end, xvacuum gives a graphical view of the safety shutters and vacuum system (valves must be open!) and finally pss_appli gives a logical diagram showing where an interlock might be.