What you'll notice
Your main decoder works perfectly but a newly added second decoder will not get signal, or the two decoders interfere with each other so that changing channels in one room affects the other.
Why it happens
The existing LNB has too few independent outputs for the number of decoders, or the setup needs a Smart LNB to run multiple decoders down a single cable and the older universal LNB cannot do it.
Adding a decoder is the point at which most households discover what kind of LNB they actually have.
What changed, and why it is better
The traditional way to feed two decoders was a twin LNB and two separate cables from roof to lounge and roof to bedroom. It works, but every extra cable run is more roof penetrations, more connectors, more places for water to get in, and more disruption to your ceilings. A Smart LNB carries multiple decoders down a single cable — fewer failure points, tidier, and usually a cheaper job overall than pulling a new cable through a finished house.
The interference symptom
If two decoders share a feed that cannot properly support them, they fight: changing channel on one causes the other to break up or lose signal, particularly when the two want different polarities. That is not a decoder fault and no amount of resetting will cure it — it is a head-end limitation and it needs the LNB or multiswitch changed.
Before you buy the second decoder
Ask us first. A five-minute conversation about what is currently on your dish will tell you whether adding a room is a simple decoder purchase or a roof visit as well — and it is much better to know that before the box is sitting on your lounge floor.
How we fix it
We assess whether your existing cabling supports the setup you want, then fit a Smart LNB or an appropriate multi-output LNB — usually avoiding a second cable run through the roof entirely.
Still not working?
If the checks above haven't restored your lnb (low-noise block), this usually needs a technician. Our Smart LNB Installation service covers exactly this fault — from R750, quoted upfront.