No Signal in one room

S

spiderplant

New Member
My Satellite Setup
I have a satellite dish with four outputs. Two outputs connect to Humax HDR 11008 Freesat box.
My Location
Oxforshire
I have a satellite dish with four outputs. Two going into bedroom and two into living room.

In the bedroom the cable connect into "RF IN 1" and "RF IN 2" on my Humax HDR 11008 Freesat box and everything works.

When I connect the same Freesat box in living room it reports "NO SIGNAL" for Tuner 1 and Tuner 2. It was working fine about a month ago. I can't think of anything that could have caused damage to the cable and cannot see any sign of damage.

Given the above am I right to assume that the there must be a problem with the cable despite so visible sign?
 
Last edited:
spiderplant said:
Given the above am I right to assume that the there must be a problem with the cable despite so visible sign?
Click to expand...
It could also be a problem with the LNB, it's not unknown for individual outputs to fail rather than all at once. Regarding the cable it could be water ingress and/or corroded connectors.
 
Have you got a satellite beeper or a multimeter?
Then you can check if the receiver voltage reaches to the LNB-side of the cable, after disconnecting the F-connector from the LNB. Caution: while disconnecting/connecting an F-plug, you can easily cause a short between core and earth of the cable! Also be cautious when using a multimeter on the F-plug.

If no, there is a discontinuance in the cable.
If yes, for instance water ingress can still be the case. Further analysis is needed.

Greetz,
A33
 
As the cable have been disconnected it could have been damaged so check the position of the centre pin of each plug (the centre part of the cable which extends into the plug) to see if it has been bent out of shape and is not connecting with the socket on the back of the receiver.
 
I would totally power down the system before disconnecting anything, you could blow the internal switch in the LNB if you accidentally short a cable out.

You can easily check the cables by making up a shorting plug with a "F" barrel connector and a small piece of wire, or by using a small alligator clip test lead from the center conductor to the outside of the cable connector.

I would disconnect all the cables at the LNB and receivers first, then using the clips check for continuity on each cable, once your sure you don't have a bad cable or two you can go to further testing with a satellite meter.

Also check the length of the center conductor, it should stick out no more then a 1/4 inch (6.5mm) from the front of the connector and should not be any further back then even with the front of the connector, too far back and it wont make contact with the socket in the receivers connector.
 
Terryl said:
.. you could blow the internal switch in the LNB if you accidentally short a cable out.
Click to expand...

Huh? How would that happen? :confused:confused

If an LNB cable has a short circuit, the damage would occur nearer to the power source, so at a diseqc switch or at a receiver (that has no short-circuit protection).
So the damage would NOT occur at the LNB side, as you wrote.

I cannot see how you would think 'the internal switch of the LNB' could be blown.

Greetz,
A33
 
Any spike in the DC voltage or current could damage an internal switch on an LNB or an external one, with 25 years of working with this stuff gives me the knowledge of what could happen.

The power source on a receiver could take a bit more abuse then the sensitive switching circuitry in an LNB or external Diseqc switch.
 
Hello
check the entire cable carefully because the wire inside can also break.
 
Terryl said:
Any spike in the DC voltage or current could damage an internal switch on an LNB or an external one, with 25 years of working with this stuff gives me the knowledge of what could happen.
Click to expand...

So, the power spike at the LNB, when you shortcircuit the cable, would be about... zero volts?
Or do I misunderstand how this power spike would occur?
I still cannot see how you would think 'the internal switch of the LNB' could be blown.

I agree that it is wise to avoid power spikes, but in this case the LNB would not be damaged, AFAIK. I would think my description/explanation still holds.

Greetz,
A33
 
If you have multiple receivers on-line there is a good or possible chance for a short when disconnecting one or more receivers with the power on.
 
Terryl said:
If you have multiple receivers on-line there is a good or possible chance for a short when disconnecting one or more receivers with the power on.
Click to expand...
Moreso if there are long runs of cable (or the receivers are connected on different phases (ie. next door/ iffy communal installations).
 
spiderplant said:
I have a satellite dish with four outputs. Two going into bedroom and two into living room.
Click to expand...
Hi
Most likely the LNB is broken.
At the LNB output, exchange the cables that go to the bedroom with those that go to the living room. Always with equipment without electrical power!
 
Terryl said:
If you have multiple receivers on-line there is a good or possible chance for a short when disconnecting one or more receivers with the power on.
Click to expand...

I didn't question the chance for a short, I did question that a short would blow the internal switch of an LNB.
I still don't see that happening.

But I think I have made my point, and explained it.
I'll not keep asking how (on earth) the internal LNB switch would blow in a cable shortcircuit situation. I still don't see it.

Greetz,
A33
 
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