Troubleshoot LNB

[boomerang]

Dish 500
Quad LNB
721
3800

We just got back last night from vacation for about 9 days. Turned on the 721 and got Downloading Info from Satellite or some similar message. It never finished the job, just hung there forever. Sorry for the vagueness, but I've been in a rush since getting home.

This morning before I left for work, I quickly ran a check switch and it failed on Tuner Two. Again, I know the nomenclature is wrong. My first step when I get home is swap leads at the 721 and see if I can get the problem to move to Tuner One, but please read on.

My dish is on a pole out at the edge of the woods. I'm in Michigan and it's cold with snow. Yes, the dish is clear of snow.

I have 4 leads buried, but only three are needed. When I buried them, I added a fourth as insurance. A couple of years ago, I had a similar problem and by swapping coax around at the ground block I got both receivers working. I was never sure if I had a bad coax cable or if it was the LNB.

A little voice in my head is telling me it's the LNB. I need to do some troubleshooting after work and was wondering how to determine if this is in fact an LNB problem. The ground block is easily accessible on the outside of my house, the dish itself is going to be really ugly to get at this time of year.

For those that will ask, I have no spare LNB to try. Also, if I do need an LNB, what model do I need with the above receivers? I don't want to add any more hardware to the system. I want to replace like with like.

 

[Liquidforce88]

If you switch cables on the back of the receiver and the problem moves, then you know the problem is not in the receiver.

Then check all you connections at the ground block.

Then check connections at the Dish.

It would come in handy if you had a toner to make sure that your cables are good from the Dish to the ground block, and from GB to the receiver.

If you don't have a toner you can try the old tounge test. Just test each lead at the dish, if you feel voltage on 3 lines that will tell you the lines are probably good. Only do this if you have no other way to test the lines.

If the lines test ok then we know that the LNB is the problem.

You have a Legacy Quad in your system.

 

[boomerang]

If you switch cables on the back of the receiver and the problem moves, then you know the problem is not in the receiver.

Then check all you connections at the ground block.

Then check connections at the Dish.

It would come in handy if you had a toner to make sure that your cables are good from the Dish to the ground block, and from GB to the receiver.

If you don't have a toner you can try the old tounge test. Just test each lead at the dish, if you feel voltage on 3 lines that will tell you the lines are probably good. Only do this if you have no other way to test the lines.

If the lines test ok then we know that the LNB is the problem.

You have a Legacy Quad in your system.

I can't thank you enough for the help. I like the tongue test!

Just curious, would a DVOM meter on the lines at the Dish be a bad thing to do? Just slightly more scientific than using my tongue! Obviously I have no toner.

 

[WiCkeDuDe]

Also try resetting the receiver then run a check switch without any lines connected. Reconnect and swap your lines then run a check switch. If the problem has swapped then you do indeed know its not the receiver.

 

[reallyniceguy]

You dont have the "check details for lnb" message on the sys info?

If you do, dish does free lnbf drift serv calls to get it replaced.

Also.. well if you tried everything.. might as well fork out the 29 dllrs for a serv call.. which is cheaper than a new lnbf. Might as well have everything else checked(if u add dhpp)

You can remove the dhpp after the serv call :X ;p

 

[iwannarock1]

If your tongue is capable of registering different voltages, then forget about using a volt meter. Otherwise.....check voltage on the back of the reciever, then check it at each side of the ground block, and finally at the lnb. If you notice a significant drop at any place, then the problem is between the last good voltage spot, and the place where the drop is.

You want minimum 12 volts at the lnb, or higher depending on what you have at the back of the receiver.

But of course, if your tongue can read different voltages, then ignore this advice

 

[denisincalif]

Another LNB Question

I guess a little knowledge is a dangerous thing. After reading a few threads in this forum, I decided to play around last night in the Installation menu on my 622. At one point I saw a note which said "LNB drift detected". But the signal levels on all three satellites I am pointed at (110, 119, 129) were all green. And I am getting all the channels I subscribe to. The only problem I have ever noticed is occasional drop outs (from a fraction of a second to [very rarely] several seconds) on my locals. But that problem is not new. It has plagued me ever since I subscribed to HD service in June 2006.

Was the "LNB drift detected" message anything to worry about? Could it have something to do with the drop outs?

 

[boomerang]

If your tongue is capable of registering different voltages, then forget about using a volt meter. Otherwise.....check voltage on the back of the reciever, then check it at each side of the ground block, and finally at the lnb. If you notice a significant drop at any place, then the problem is between the last good voltage spot, and the place where the drop is.

You want minimum 12 volts at the lnb, or higher depending on what you have at the back of the receiver.

But of course, if your tongue can read different voltages, then ignore this advice

Well, I cheated and started outside. Voltage was good on both sides of the ground block. Went out to the dish and two of the 4 connectors were completely corroded. The center conductor was non-existent. I put new ends on and and new barrel connectors, ran a check switch and all is good with the world.

When the weather breaks, I'm going to have to get out there and put good weather proof connectors on. You know how it is, this stuff always happens at the worst possible time.

Thanks to all for their advice! :

 

[Liquidforce88]

If your tongue is capable of registering different voltages, then forget about using a volt meter.

But of course, if your tongue can read different voltages, then ignore this advice

Damn I have been doing this for too long

 

[Fredinva]

Damn I have been doing this for too long

It's called 'black tongue disease' !!!
But I never got it from 9 volt batteries.

fred

 

[UGAChance]

I guess a little knowledge is a dangerous thing. After reading a few threads in this forum, I decided to play around last night in the Installation menu on my 622. At one point I saw a note which said "LNB drift detected". But the signal levels on all three satellites I am pointed at (110, 119, 129) were all green. And I am getting all the channels I subscribe to. The only problem I have ever noticed is occasional drop outs (from a fraction of a second to [very rarely] several seconds) on my locals. But that problem is not new. It has plagued me ever since I subscribed to HD service in June 2006.

Was the "LNB drift detected" message anything to worry about? Could it have something to do with the drop outs?

It adjusts the tunes automatically, but it is stating that your LNB is BAD. The oscillator has drifted out of spec.

Call DISH and say you are having dropouts and you see the Check LNB for Details message.

 

[denisincalif]

It adjusts the tunes automatically, but it is stating that your LNB is BAD. The oscillator has drifted out of spec.

Call DISH and say you are having dropouts and you see the Check LNB for Details message.

Thanks. I will do that in the next day or two.

 

[highdefjeff]

Caution!!!

If you switch cables on the back of the receiver and the problem moves, then you know the problem is not in the receiver.

Then check all you connections at the ground block.

Then check connections at the Dish.

It would come in handy if you had a toner to make sure that your cables are good from the Dish to the ground block, and from GB to the receiver.

If you don't have a toner you can try the old tounge test. Just test each lead at the dish, if you feel voltage on 3 lines that will tell you the lines are probably good. Only do this if you have no other way to test the lines.

If the lines test ok then we know that the LNB is the problem.

You have a Legacy Quad in your system.

Have you ever tried to make the connection to the groundblock after plugging in the receiver, and the house is incorrectly wired? A very large and loud arc of bright blue-white light can jump a couple inches! This experience made me use the tongue only in extreme circumstances or if I've already checked the wiring. BE CAREFUL! Incorrect home wiring can send way more than 18 volts down the line!

 

[highdefjeff]

I guess a little knowledge is a dangerous thing. After reading a few threads in this forum, I decided to play around last night in the Installation menu on my 622. At one point I saw a note which said "LNB drift detected". But the signal levels on all three satellites I am pointed at (110, 119, 129) were all green. And I am getting all the channels I subscribe to. The only problem I have ever noticed is occasional drop outs (from a fraction of a second to [very rarely] several seconds) on my locals. But that problem is not new. It has plagued me ever since I subscribed to HD service in June 2006.

Was the "LNB drift detected" message anything to worry about? Could it have something to do with the drop outs?

The drop outs probably indicate a poor alignment of the dish with respect to 129. You need a tweak.

 

[ped832]

Have you ever tried to make the connection to the groundblock after plugging in the receiver, and the house is incorrectly wired? A very large and loud arc of bright blue-white light can jump a couple inches! This experience made me use the tongue only in extreme circumstances or if I've already checked the wiring. BE CAREFUL! Incorrect home wiring can send way more than 18 volts down the line!

One day had a receiver all plugged in ready to go, everthing but the sat cable. One hand on the receiver, grabbed the f-connector to hook up. WOW Got my world lit up! I keep remembering that event everytime I use the tongue technique (yeah, I still do) and wonder what if???

 

[UGAChance]

Dish 500
Quad LNB
721
3800

Whoops... my eyes must have glazed that you have a 721... The 721 doesn't have LO Drift compensation in the software and I do not think 3800 does either yet.

So, signal will drop out if you are on the edge of +/- 5 megahertz drift from the center(nominal) tune. The tuning card/chip will lock on drift in the +/- 5 range.

Tell DISH you are losing signal and see the LNB Drift Message.