There is about 100 reasons
bad 119 lnb
Bad 119 side on Dual type head
Dish skew off
Dish not aimed properly
Bad multiswitch
Bad port on multiswitch
119 not connected to multiswitch or sw 21
Please list as best you can exactly what receivers, what dish type etc you have.
Pictures of setups help alot too!!!
Don't forget cable problems! Why do guys always want to replace equipment first before checking the cable?!?!?!?! Sheesh..... If it only shows 110 Feed in the switch matrix with no other boxes with X's in them, then it's a cable problem. Otherwise it could be dish alignment or equipment.
Could be snow/ice on the LNB, cold-related switch failure, winds knocked the dish out of alignment (not likely, as that usually causes all satellite signals to go away)...
Like dodge said, what is your receiver and dish setup?
About 4 times a year (and especially after power outages), I lose programming from 119 on my 625. I run "check switch" and verify I get 110 but not 119. I clear the switch configuration (disconnect LNB, run "check switch" until it runs through 40 or so tests with "X"s everywhere) and reconfigure it (hook back up LNB, run "check switch") and everything works again.
It's best to check dish aiming, cabling, etc. before doing the switch config thing, IMHO.