Complete Loss of Signal

[tirosh]

Guys,

I need some help. While my wife was watching her favourite program on 42E she got a "no signal". This was not surprising at first because it's one of the Encrypted channels in the Digi Star packet. The thing is that since then I cannot get a signal on any of the channels on 42E, or any of the other birds (Hotbird, Astra etc) for that matter.

I am using an Echo AD3600 with an MM v1.03 and Penta 1.11. I removed the CAM in case this was causing the problem and played around with the Sat positions without any success. I have also checked the cables at the back of the receiver and also at the LNB end, and they all seem to be connercted ok.

Does anyone know what could be wrong? Could the LNB have gone? I am at a complete loss and any help would be appreciated.

Tirosh.

 

[haga]

It's possible the LNB has gone, but unusual, they normally give a bit of warning (like sparklies etc) as you have lost all signals though this may be the LNB, I take it you've done a check in the echo's menu to check signal strength etc, cheapest option seems to change LNB, if you've checked all the connections and coax there doesn't seem to be anything else you can do. Try taking the mains out for 30 seconds, then plug it back in and see what happens, dont forget to take mm out before you do this.
haga

I'm in Essex, I have a spare lnb if you need it.

 

[rolfw]

Also worth checking whether the receiver is powering the LNB, licking the coax end at the LNB will do it, but a volt meter or 12v bulb will be better. If there is power to the LNB, then check if a complete power down and software restart(disconnect from mains) cures the problem, it may also work if the short circuit protection has been triggered for some reason.

 

[tirosh]

Thanks for your replies guys. I have tried powering down the receiver for an hour but this didn't make any difference.

So the next thing I decided to do is to start at the receiver end and work towards the LNB to try and isolate the problem. I removed my receiver and took it to a friends house. There I plugged it into his setup and could pick up the Analogue reception (not sure if this was because of his LN but at least it showed that the receiver was able to receiver signals. Brought it back to my house and still no joy.

I guess this tells me that the problem has to be either with the Coax or the LNB (possibly the dish but that is less of a possibility as with 1.2M dish I should at least get some sparklies on the Analogue channels.

What's the best way of checking the Coax / LNB? Do I need to go out and buy replacements?

Tirosh.

 

[rolfw]

Most coax faults are not immediate Tirosh, you would normally find some degredation over a period of time. Connector problems normally only occur if something has been moved, typically behind the TV for dusting etc, or cuts and dents. Can you check to see if there is a voltage at the LNB end of the cable and the connection is good?

If the programme went off suddenly, it is unlikely to be dish alignment (Unless hit by a football or something heavy), so the LNB would perhaps be the logical offender, assuming all of the other things check out.

 

[tirosh]

You have echoed my thoughts exactly Rolf. The fact that it went suddenly in the middle of watching a program makes me highly suspicious of the LNB as well. Even if the dish had moved a bit the fact that I went from 42E -> 19E -> 13E -> 10E and back again, trying adjustments all the way would have I am sure corrected the minor mis alignment.

Can you check to see if there is a voltage at the LNB end of the cable and the connection is good?

That is my next task. What is the voltage that I would expect to see at the LNB end of the Coax?

Tirosh.

 

[Channel Hopper]

Depending on the polatiry set within the receiver, you should see between 13 and 18 volts at the far end

You could preempt climbng the ladder by checking a voltage is present on the tuner first, and this would then allow you to confirm that nobody has put a nail through the cable first when you finally go outside

I havent heard of problems with Echostar tuners, but there were reports on earlier models wrt the power supplies, but there is always the chance you are the first.

 

[tirosh]

Thanks CH.

Fortunately I don't have to climb a ladder to do the checks at the dish end as it's on a pole in the garden.

Does the fact that I was able to receive analogue signals at my friends house on my receiver not tell us that the receiver is powering the LNB ok?

 

[2old4this]

that certainly tells you that the analogue tuner is working. Echostar analogue+digital receivers actually have two separate tuners. One analogue, one digital. Why didn't you test the digital reception too, since that is what you needed? Or did you, and it failed?

My guess is the LNB. I've had two go on me and this is exactly what happened. I got no warnings or sparklies. In one case, the fault was only on the H reception (I could still receive all V signals but nothing horizontally polarized). In any event, most standard universal LNB's are cheap enough. I'd replace it if I were you.

2old

 

[tirosh]

2old4this,

The place where I checked out the receiver only have an analogue setup at the moment. I suspect that their LNB is not a Universal LNB and that's the reason that I was not able to get any Digital channels (only a guess though).

It's good to know that other LNBs have gone in the same way. I'll get a replacement and try that. Which one would you recommend 2old? Is the MTI Blue Line still considered to be one of the better ones?

Tirosh.

 

[2old4this]

so you still don't know for sure whether it's your LNB or you digital tuner.
Do you have a Sky digibox? If so, you could connect that up and try looking for signals (use the add channels feature to scan a specific transponder, but the Symbol-Rate has to be 22000 or 27500)
Have you tried looking for signals on both H and V transponders? If the LNB has failed on just one, then at least reception of the other would prove that the digital tuner itself is ok.

My advice now: take your receiver along to your local friendly satshop and test it on one of their dishes/LNBs before you replace your LNB.

I have no advice to offer on the actual LNB I'm afraid. Best I've come across are from Swedish Microwave but the differences are marginal. Go for the cheapest 0.7db universal you can find (unless you're a real DX-er).

2old

 

[Channel Hopper]

Does the fact that I was able to receive analogue signals at my friends house on my receiver not tell us that the receiver is powering the LNB ok?

From memory, I believe the way the receiver supplies power to the LNB is through the digital tuner, the analogue is simply 'slaved' off using the loopthrough lead for signal only

Testing it at your friends on analogue could also mean a fixed LNB voltage is being supplied, giving you signal, but the lack of switching is affecting recption at your place, but it is somewhat unlikely.

Since the LNB is reachable, I would go and check the voltages first, and then go out and buy an LNB.

 

[tirosh]

2old, CH - Thanks for the advice.

- When I get home from work tonight I will check the voltage on the cable.
- Then I wil try and test my receiver at another friends who has the same setup as me
- Finally I will get a replacement LNB as they are not that expensive anyway.

Hopefully one of these will fix the problem.

Tirosh.

 

[tirosh]

I have now got to the bottom of this issue and want to let people know the situation (in case it helps others).

1) I started at the receiver end and worked my way up to try and isolate the problem. I tried the receiver at my brothers place and determined that the receiver was able to receive both analogue and digital receptions.

2) Next I thuoght that either the cable or LNB was at fault so I got a replacement MTI Blue LNB and tried that. Still no signal

3) So I thought that the cable must be at fault so I got some replacement Coax and tried that. Still no sinal.

4) I took voltage and resitance readings on the cable at the LNB end and was able to get both short circuit and open circuit readings as well as 13 and 18 volt readings.

At this point I started to get really baffled and was certain that the only thing which could now be at fault was the Dish. How could this be? The signal had gone in the middle of the day whilst watching other programs!! To be 100% certain I took my receiver, spare cable and replacement LNB to my brothers place and hooked it up to his dish. Everything was showing fine. This proved it 100% that somehow my dish had become mis-aligned as I was not able to get any reception from any sats, including Astra and Hotbird.

Finally I managed to adjust the dish to get some reception, not ideal for all sats, but good enough for now. That's the way I left it as I am now taking a few days break and will try again next weekend.

I hope this helps others.

Tirosh.

 

[rolfw]

That's certainly unusual for the dish alignment to go suddenly Tirosh, perhaps it was slowly moving on the pole mount.