When you are trying to use the analog input, what sync source are you using ? Have you tried others ?

When you connect to the analog inputs, what cables are you using ? Have you made sure that all pins (1,2 and 3) of the XLR are connected to something ? My guess is that either pin 2 or pin 3 are unconnected, or that if you connect to the 1/4" you are using a tip-ring-sleeve cable, and again one of the pins is unconnected. See p.9 of the User manual.