[rbpeirce]

I checked the other postings on this topic and they don't match.

Without any storm or other reason I could identify I lost all my even transponders. I tried restarting the DVR and that didn't help, so I unplugged it for five minutes and rebooted. Problem solved and I have been okay now for three days.

So, can anybody guess what happened and is it likely to happen again?

 

[jimmie57]

I would suspect a faulty connector in the coax. It could have gotten wet or it is a little bit corroded inside or even just be loose.

 

[Diana C]

What is your installation like? If you have a legacy setup (non-SWM) it could have been a software glitch in the DVR that caused it to not switch voltages (which is how it selects between odd and even transponders). A SWM setup would be a bit different, the odd/even selection is done at the SWM switch (either outboard or in the LNB). To lose an entire polarity bank of transponders would more likely indicate a switch error.

 

[veryoldschool]

To lose an entire polarity bank of transponders would more likely indicate a switch error.

Could be something as simple has a loose coax connection too.

 

[rbpeirce]

I suspect a software glitch since rebooting it solved the problem. I'm just curious about the likelihood of it happening again. In other words, could something be failing in the unit or could it just be something totally random.

 

[veryoldschool]

I suspect a software glitch since rebooting it solved the problem. I'm just curious about the likelihood of it happening again. In other words, could something be failing in the unit or could it just be something totally random.

:shrug:
From my own experience, I'd be leaning towards a loose connection.

 

[RBTO]

Your problem makes sense because two separate antenna circuits are used for odd and even transponders (they alternate in polarization). If something killed one of these circuits, it would produce the result you're observing, however it could be any number of other causes (those mentioned) as well. Is this true of all satellites or just one (101 only)? If it's just one, the problem is in your antenna. If it's all, the problem is most likely elsewhere. Corrosion can sometimes act like a diode and pass only one polarity. Polarity is the means used to select odd/even and if this happens, the odd or even may drop out as previously mentioned. It's less likely the receiver is at fault, but still possible.

:new_sleepOOps! I missed the part about rebooting and curing the problem - it most likely was a software glitch!

 

[veryoldschool]

Corrosion can sometimes act like a diode and pass only one polarity. Polarity is the means used to select odd/even and if this happens, the odd or even may drop out as previously mentioned. It's less likely the receiver is at fault, but still possible.

Not a diode, but a resistor.
If it were a diode, the voltage polarity would need to switch, but it doesn't.
It only changes between 13 volts and 18 volts.

 

[carl6]

More information on your system would help, but the following might help you understand the possible problems. A software glitch really isn't the likely cause.

The dish has what is known as a stack plan. There are four combinations of channel groups, and only the applicable group is sent from the LNB to the receiver.
1) 13 volts, no tone
2) 18 volts, no tone
3) 13 volts, 22KHz tone
4) 18 volts, 22KHz tone

You can get more information on this here: http://hr20.dbstalk.com/docs/Dish, Multiswitch and Cable FAQ.pdf

Even transponders are associated with the 18 volt signal while odd transponders are associated with the 13 volt signal. If there is too much voltage drop between the receiver and the LNB, you will lose the even transponders. Many things can result in the voltage drop, typically corroded or wet connectors, very long coax runs, bad grounding blocks or splitters, the wrong type of coax, etc. Your system may be just above the threshold of showing problems, and something caused it to drop below that threshold. That's where a bad or corroded connector can typically show up.

 

[rbpeirce]

It is an R15-300 with a round dish, a single LNB and two cables. As far as I recall it never lost either the even or odd transponders before and after rebooting hasn't lost them since. The connections are tight and the signal was 0 on both tuners. It only gets 101 so I couldn't check other satellites.

Because it is unlikely both cables would flake out at the same time and recover without any attention, I am inclined to think it was the DVR. Of course, I am assuming it puts out one voltage signal to both lines at the same time, which is the only thing I can think of to explain this.

As before, I am wondering if loss of voltage is a fluke or a symptom of a developing problem.

 

[jimmie57]

It is an R15-300 with a round dish, a single LNB and two cables. As far as I recall it never lost either the even or odd transponders before and after rebooting hasn't lost them since. The connections are tight and the signal was 0 on both tuners. It only gets 101 so I couldn't check other satellites.

Because it is unlikely both cables would flake out at the same time and recover without any attention, I am inclined to think it was the DVR. Of course, I am assuming it puts out one voltage signal to both lines at the same time, which is the only thing I can think of to explain this.

As before, I am wondering if loss of voltage is a fluke or a symptom of a developing problem.

No one can know for sure, but problems like this do have a tendency to return unless something is done to prevent it.
If it is software as you suspect, whatever caused it will cause it again when the sequence of operations that caused it last is followed again, probably.

If it were a connector, resetting the machine could have very easily reestablished the faulty connection for now. When this marginal connection is working now something could very easily break this weak connection in the near future. It could be wind, rain, heat from the sun shining on the connector.
No one can know for sure without actually examining all connections, etc.
This would involve the actual opening up each connection and visibly checking inside the area and putting them back together.

 

[Diana C]

With a round dish and no multi switch, each tuner will alternate between 18 and 13 volts as required, depending on the transponder the selected channel is on. To have both tuners lose all the even transponders at the same time would indicate either a signaling problem at the receiver, or a LNB problem at the dish. If the problem does not recur, it was probably just a transient glitch (I had an old RCA receiver that sometimes just refused to switch to 18v). If it reappears, I'd suspect that the LNB might be failing. The reset of the receiver could have cleared the problem at the LNB by removing all voltage from the LNB (IOW, it reset the LNB too). It could also be a hardware issue at the receiver, but I'd suspect the LNB first. Seeing the failure on both tuners, with no multi switch, makes cabling issues less likely, IMHO.

 

[jimmie57]

It is an R15-300 with a round dish, a single LNB and two cables. As far as I recall it never lost either the even or odd transponders before and after rebooting hasn't lost them since. The connections are tight and the signal was 0 on both tuners. It only gets 101 so I couldn't check other satellites.

Because it is unlikely both cables would flake out at the same time and recover without any attention, I am inclined to think it was the DVR. Of course, I am assuming it puts out one voltage signal to both lines at the same time, which is the only thing I can think of to explain this.

As before, I am wondering if loss of voltage is a fluke or a symptom of a developing problem.

Please clarify the bold text above. Was all of the transponders reading zero or just the 18volt ones ?
Thanks

I do agree that it would be odd to have this happen in 2 coax lines if it were a connection.

 

[rbpeirce]

To have both tuners lose all the even transponders at the same time would indicate either a signaling problem at the receiver, or a LNB problem at the dish.

I hadn't considered the LNB. If that goes, I have an oval dish in the closet with three LNBs of which I know one is bad. I guess it is possible, but how difficult would it be to aim that dish so that the 101 sat would hit one of the good LNBs?

On the surface it looks like it would be possible but difficult. Does anybody know?

 

[veryoldschool]

I hadn't considered the LNB. If that goes, I have an oval dish in the closet with three LNBs of which I know one is bad. I guess it is possible, but how difficult would it be to aim that dish so that the 101 sat would hit one of the good LNBs?

On the surface it looks like it would be possible but difficult. Does anybody know?

You can't "align the dish" to use the good LNB.
If the 101 LNB is bad on that dish, you can't use it.

 

[rbpeirce]

You can't "align the dish" to use the good LNB.
If the 101 LNB is bad on that dish, you can't use it.

Thanks. I guess if it does go I will need to buy one somewhere, maybe an entire dish on eBay.

 

[jdspencer]

SolidSignal has the dual output LNB.
http://www.solidsignal.com/pview.as...Out-LNB-(ZKFG52N)&c=Satellite Components&sku=

 

[rbpeirce]

That's not quite the LNB I have. Mine has a bend on the bottom that slides into a rectangular tube that connects to the dish. There is a hole for a single bolt through the middle.

Checking out the web site it appears the Gardiner unit at $32.95 is probably the one I want. However, it looks like I can buy that LNB on eBay for less than $20.

http://www.solidsignal.com/pview.as...lacement-Dual-LNB&c=Satellite Components&sku=