Tvheadend

Hi everyone

I need some help here, i looked up in the forum but i didn't see any solution.
So, I got a cine S2 v6.5 (4 tuners s2), tvheadend can see the four tuners, but
some muxes have "fail" for scan result (Astra 19.2,no channel found, no service).
I made these tests: i tried with enabling each tuner (and disabling all others),
result is the same.Scan is very quick, signal strength and snr are above 70%.
One of the mux have service but no channel, what should i do now?

Thanks again for helping me

ps here s my system config: ubuntu 14.04lts (core 2 quad q9550,8gb ram,HD 80gb),
Tvheadend 4.07, digital device cine S2 v6.5