What would cause LNB's to continuously fail?

[kewl1]

I have a 3 dish set up. One for BEV and 2 for DN. The DN dish that is pointed at 119W keeps failing. I get no signal at all ie 00 but Q of 73 right now. So no signal but fine quality. This could only happen to me.

This started last year and after checking out everything I could think of I wondered if it could be the LNB. I was told by people that are much more experienced than me like a guy who used to install sats for a living, as well as the guy in the sat store, that LNB's never fail. The sat store guy hated to take my money for a new LNB. Low and behold that fixed my problem.

But now I have bought two new ones and this last one only lasted a couple of weeks. It's always the same dish. I really have no expertise in this area at all. The switch thingy seems ok. When I put on the last LNB I switched ports and it worked fine.

Any ideas would be greatly appreciated.
Thanks all
:rotflmao:

[panmanzaa]

kewl it may be your disque swt try putting it on another port --1 or 2, but remember to change it on your sat diesq spaceon installitions-to chan search.

[Costactc]

If your getting signal of 73% then your lnb is fine, your dish needs to be tweaked for 119 or as panmanzaa mentioned in previous post check your switch settings.

[satchick]

I think he said he's getting Quality of 73... Did you test the suspect LNB on another dish?

Is your system grounded? There could be some transient voltage on the lines causing a problem. Also make sure that there are no shorts or opens in the coax going to that LNB, might as well check the whole system while you've got the meter out. Don't forget to check out the connectors for possible water intrusion which can cause an intermittent short. If the system is grounded properly (It's a code requirement BTW), and the coax checks out fine, try replacing the switch.

[jvvh5897]

Hum....
" I get no signal at all ie 00 but Q of 73 right now"--to have a Q reading, but no signal reading would be an indication of a box problem to me.

"This started last year"--so it did work just fine for a time, it seems--that does not indicate something like grounding problem to me.

"LNB's never fail."--they do, but it is not common. they can fail because the voltage delivered to them is reversed, or too high--you should likely check what the box is giving it by using a multimeter (you can pick up a cheap one for $10 - $20 US, even walmart has a cheap one but I like to go to circuitspecialist's site for mine). There can be bad voltages going to an LNB if ground problem in your house circuits that can deliver part of AC line voltages to stuff--there are simple pluging gizmos to test house wiring for this type of thing, but usually the problem only shows up if boxes are run off of different plugs and if you use a common power strip for all the boxes this should not be a problem. If you ground something around the dish and you get a spark then this could be a problem for you, but it would likely happen the second you hooked up LNB and not develop over time (or possibly when the ground becomes conductive--like after a shower).

Have you considered moving an LNB over to the DN dish that you don't have trouble with? THere is something called the "poor man's dish" that just ties the second LNB right next to the first on the dish and uses reflection to get signal to 2nd LNB. Maybe then you could test other things about the 2nd dish for troubles.

[kewl1]

kewl it may be your disque swt try putting it on another port --1 or 2, but remember to change it on your sat diesq spaceon installitions-to chan search.

Changing the port is one thing that I did try but with no luck

[kewl1]

I think he said he's getting Quality of 73... Did you test the suspect LNB on another dish?

Is your system grounded? There could be some transient voltage on the lines causing a problem. Also make sure that there are no shorts or opens in the coax going to that LNB, might as well check the whole system while you've got the meter out. Don't forget to check out the connectors for possible water intrusion which can cause an intermittent short. If the system is grounded properly (It's a code requirement BTW), and the coax checks out fine, try replacing the switch.

No I don't think it is grounded. I wondered if water getting in could do harm so that is another thing I will try. I'll get a new wire with new connectors and buy a new switch even though the switch seemed to work ie I can make the same sat work on different ports.

[satchick]

I wondered if water getting in could do harm so that is another thing I will try.

Water getting in is very bad... It'll corrode the conductors, and water will also migrate up the cable as well. There are sealants designed to help prevent that, and just making a drip loop before connecting to switches helps as well. The switch should also be mounted with the ports horizontal to prevent water flowing into the connectors and switch.

[kewl1]

Hum....
" I get no signal at all ie 00 but Q of 73 right now"--to have a Q reading, but no signal reading would be an indication of a box problem to me.

"This started last year"--so it did work just fine for a time, it seems--that does not indicate something like grounding problem to me.

"LNB's never fail."--they do, but it is not common. they can fail because the voltage delivered to them is reversed, or too high--you should likely check what the box is giving it by using a multimeter (you can pick up a cheap one for $10 - $20 US, even walmart has a cheap one but I like to go to circuitspecialist's site for mine). There can be bad voltages going to an LNB if ground problem in your house circuits that can deliver part of AC line voltages to stuff--there are simple pluging gizmos to test house wiring for this type of thing, but usually the problem only shows up if boxes are run off of different plugs and if you use a common power strip for all the boxes this should not be a problem. If you ground something around the dish and you get a spark then this could be a problem for you, but it would likely happen the second you hooked up LNB and not develop over time (or possibly when the ground becomes conductive--like after a shower).

Have you considered moving an LNB over to the DN dish that you don't have trouble with? THere is something called the "poor man's dish" that just ties the second LNB right next to the first on the dish and uses reflection to get signal to 2nd LNB. Maybe then you could test other things about the 2nd dish for troubles.

Lots of things here for me to try . Thanks very much

[kewl1]

Water getting in is very bad... It'll corrode the conductors, and water will also migrate up the cable as well. There are sealants designed to help prevent that, and just making a drip loop before connecting to switches helps as well. The switch should also be mounted with the ports horizontal to prevent water flowing into the connectors and switch.

My swith is just hanging and the ports are verticle. This is something I can correct. I wondered aboiut water because the other two LNB's seem to fit on tightly but this one that fails is kind of loose and can move slightly even after tigtning as much as I can.