DM800HD from china switch station failed

[richiesgr]

I'd like to ask help from people or instaler
After adding a LNB and a Disecq my the DM800 refuse to switch channel I get "Tune Failed" all the time the only way to get it work is to connect a second receiver like a magnum and connect the dream to the LNB out of the magum.
I suspect a problem with the tuner power of the DM.

Do you think there is something to do like install a more sensible LNB or buy a better quality Disecq or there is nothing to do and just stop using the DM

Thanks for any help

Sorry for english but In hebrew it'll take me a week to write this

[zach]

on the satelline cofiguration, set to " increase voltage " on that particular lnb