3 bxes in one house

Have a bit of a head scratcher,have 3 sat boxes in my house,1x500db 1x800hd and just added a openbox.the 2 db's were and are working fine but the openbox is only clearing certain channels,some movies,some sports etc but not them all.have the 800 and open on the same dish,500 seperate dish have all 3 hardwired.have 2 subs with same guy and the other one from a different provider.anyone got any ideas.

800 and open 2 seperate freeds from quad lnb from 60cm *** dish,tried the 500 in place of the openbox and the 500 worked fine put the openbox where the 500 was still doing the doing the same only half the channels..Will try tomorrow switching them all around again.just thought someone else might have had this prob .Will update tomo night. Thanks

Have done mate first thing i thought of as well lol.

Update after hours of swopping boxes lines etc discovered it was a carpenter's stray nail that was the problem,went through the cable but left enough strands to leave some signal,glad i got it sorted was driving me nuts lol.