Set it to DiSEqC 1.0 port A or B.
FYI
@confusedperson
Having briefly scanned this thread again, I'm rather confused myself about "where we are" in trying to solve your problems, but I will try to clarify a few things that maybe are needed!
Firstly I think your understanding of what is in your TV
may be incorrect because -
unless it has 4 separate connectors for satellite LNB cables (which would be extremely unusual) - it does NOT itself incorporate a DiSEqC 1.0 switch but it includes circuitry that IS capable of controlling a separate external 1.0 switch by sending the correct commands.
Then, confusingly, the ports on 4-way DiSEqC switches can be marked
either as Ports A, B, C & D,
OR as Ports 1, 2, 3 & 4 - it doesn't actually matter as long as you realise that A=1, B=2, C=3 and D=4! - I have seen LNBs and DiSEqC switches marked both ways.
Typically, "dual LNBs"
(as you called it above but somewhat incorrectly IMHO - see below) intended to pick up 2 separate sats are known as "
monobloc" LNBs and incoporates what is known as a "MiniDiSEqC" 2-port switch, and the ports are marked/referred to as Port A & Port B - with Port A often (but not exclusively!) the one that is to be aimed at the sat directly "in front" of the feedarm on which it is mounted, and with Port B offset to one side or the other (depending on which secondary sat is targeted.)
The cable from such a monobloc LNB with a MiniDiSEqC switch can then go to:
- as in your case, to the TV sat input and with the receiver setting to be Port A & Port B as appropriate;
- if one also wants to connect LNBs for other sats, then you would connect the cable from the monobloc to a port on an external DiSEqC 1.0 switch, with the other ports for the other sat cables
However, from this point onwards I will defer to other forum members as to how to set up a MiniDiSEqC switch in a monobloc in that configuration because, TBH, my experience with monoblocs was itself "confusing" and "not encouraging" and so I don't use them as I felt their use to be more trouble than it was possibly worth.
BTW, with respect to the term "dual LNB",
or more commonly "Twin LNB", those terms conventionally refers to an LNB assembly which actually incorporates TWO separate LNBs but pointed in exactly the same direction - typically for receiving two separate channels on the same satellite,
not on two different ones!