Today my downstairs Multiroom MySky HDi had no signal, however upstairs unit was working fine.  Tried a reboot as this seemed to fix it before.  But not this time.

The Sky dish has a quad output LNB, 2 outputs are utilised in my house upstairs/downstairs, the 3rd & 4th outputs go to a granny flat via a twin cable (the tenant currently doesn't have Sky).
The dish is quite accessible so to get my downstairs unit functioning, I unplugged the 1st RG6 from it's output and swapped it for the 3rd output.  Soon as I did this the MySky unit regained signal and started working again.

I assume this means the LNB is dying, i.e. it's first output is now dead.  
If I ring Sky and advise will they replace with a new quad output LNB?