Quad LNB seems to prevent dish motor from working?

ksada2

Hi guys,

Yesterday I replaced my existing LNB with a Thomson Quad LNB (part no 13422). Since then the dish motor moves around from sat to sat around 4 times, after which it fails to move completely! The green light on the motor also goes out at this point.
I can reboot the receiver, which sometimes brings the motor back to life, but generally not.
I have two cables connected to the LNB, one from the main receiver via the motor, obviously, and the other one is not yet connected to a receiver, though I cannot imagine that is the cause. The connectors on the LNB are marked P1 P2 P3 and P4. I have tried different combinations and that had no effect on the problem.

Just to ensure the motor is not faulty I refitted the orginal LNB today, and it works beautifully.

This baffles me, can anyone else throw light on this for me please?

Cheers,
Alan

Robbo

Hi Alan,
In the absence of any other replies so far, I was wondering if it was worth terminating the unused outputs of the LNB to see if that makes any difference.

Another thing that possibly might cause a problem is that the new LNB may be drawing too much current and not leaving enough for the motor. If the down lead is long there also may be insufficient current available from the receiver. The Diseqc standard states that the Diseqc compatible receiver must supply at least 500mA, but with a quad LNB, a Diseqc motor, and possibly a long lead, maybe it's just not enough.


I believe that you can get 'DC power boosters' that are placed somewhere in the lead, but I know nothing whatsoever about them.

I can only speculate I'm afraid.

ksada2

Hi Robbo,
I will suggest terminating the outputs to my Dad and see what he says.
Someone in another forum also suggested that the LNB may be draining too much power from the cable and not leaving enough for the motor.

I thought I read in the dreambox manual that I can increase the power output, but typically cannot find that information now I need it. I'm not sure whether that can also do harm in other ways though.

I'm also wondering if it would solve the problem when I connect our second receiver up... but I guess it would only solve it if the stb was permanently switched on....

The mystery continues!

Robbo

As an experiment, you could try dragging the receiver to the motor and connect just using a small length of cable, to see if it works ok.

Poor connections on the cables may also cause excessive DC resistance,
reducing current flow.