Water in LNB?

[Halr]

Hey guys,

I have a friend that has a 1st generation slimline dish, with the clear style lnb covers. He is having signal degridation issues, especially when cloudy/rainy. SO... I was going to be bop over there, put a meter on it and align it.. Now, I learned that through the clear feedhorn cover, on the center 3 feed feedhorn, he can see condensation. 99-101-103 signals are low, 110-119 signals good. He does not have the $5 a month warranty, and has had the system since early last fall. So, here is my question.

In the old style LNB's/Feedhorns, from back in my C band days, the actual feedhorn was sealed away from the electronics. Has anyone tried to disassemble, dry and reseal one of these style LNB's? I assume that condensate is not desired, and that it is supposed to be water proof. But, maybe I am assuming wrong? Is the feedhorn cover sealed to the unit, or is it removable with out damaging. I am thinking that I can remove it, air dry the internals, and reseal the cover back on.. I wonder how many people have this issue, and don't know, or have the newer white plastic, and would never know if there was moisture under the cover?

Any thoughts?

[BattleZone]

Leaking LNBs are damaged and must be replaced. The feedhorn is NOT separate from the circuit board (I've taken them apart).

[Halr]

that figures.. do you recall what the actual antenna looked like? is it possible to clean any corrosion or residue off of it? I was wondering if drying with contact/electronics cleaner and removing any residue from the actual antenna down in there would revive it.

[K4SMX]

that figures.. do you recall what the actual antenna looked like? is it possible to clean any corrosion or residue off of it? I was wondering if drying with contact/electronics cleaner and removing any residue from the actual antenna down in there would revive it.
You can play with that idea after they install his new LNB under the Protection Plan....:)

[Halr]

You can play with that idea after they install his new LNB under the Protection Plan....:)

ah.. see.. that is the hang up. he doesn't have the monthly fee for the protection plan. He was thinking that if it was leased, it was theirs to take care of, as far as hardware failures went. they want to charge for the service call and parts. I don't know about the plan, I own my stuff, and don't have the plan either. So I was going to get a new lnb assy off ebay or satguys, but thought I would give a repair try first, if we can get it dry, remove any corrosion and reseal it.

[carl6]

I have a CalAmp LNB assembly here (which has the transparent covers like you mention), and I was able to pop the plastic cover off using a small flatblade screwdriver around the joint between the plastic and metal. It came off all too easy (which is probably why/how yours got moisture in it to start with).

I've also been inside the back of this unit to modify it for 99/101/103 use only (disconnecting 110 and 119 electronically inside). From the back/inside, there is no way to get to the area of concern without disassembly way beyond what you would be able to put back together.

You might try popping the cover off, drying everything, and putting it back on with a bead of silicon around the seam.

Carl

[Halr]

You might try popping the cover off, drying everything, and putting it back on with a bead of silicon around the seam.

Carl

that is just what I am thinking too.. A good spray out with some electronics grade contact cleaner, alcohol the antenna pin/pad, and reseal with sillycone...

What can possibly go wrong?

:D

I was hoping for some experience in the internals, as to what I will find down in the feedhorn. What is used as the actual antenna? If anyone knows if it is a pin, or a flat pad or the like? If anyone had any pictures, of one disassembled, at any level, that would be great also!

thanks!

[BattleZone]

The antenna is just a thick trace on the circuit board. But, again, if water gets into the feedhorn, the entire circuit board has been exposed and subject to corrosion and DC power-related damage.

[BattleZone]

http://rene.balderacchi.club.fr/illustrations/LNB%2002.jpg

This isn't a DirecTV LNB, much less a slimline LNB, but you can get an idea of what the "antenna" looks like. The antennas on this LNB are the traces at approx 12 o'clock and 3 o'clock in the circle on the right side of the board.

[K4SMX]

You might also need a hair dryer. :)

Standalone Slimline LNB's are something I'd be very careful about buying on eBay. They're not often listed, and when they are, you have to wonder about them. I have investigated buying them separately, and they're not readily available. I had tried to buy a large quantity of them, and the distributor just didn't stock them as a separate item. The way it was explained to me was that that the cost of the LNB was a very high percentage of the cost of the entire dish. Buying a new dish might be a more reliable although kind of ridiculous way to go.

[RobertE]

You might also need a hair dryer. :)

Standalone Slimline LNB's are something I'd be very careful about buying on eBay. They're not often listed, and when they are, you have to wonder about them. I have investigated buying them separately, and they're not readily available. I had tried to buy a large quantity of them, and the distributor just didn't stock them as a separate item. The way it was explained to me was that that the cost of the LNB was a very high percentage of the cost of the entire dish. Buying a new dish might be a more reliable although kind of ridiculous way to go.

Add in the fact that for the most part, the LNBs are not packed separately from the dish. So, to get the LNBs, you have to open up a box anyway.

This is changing very soon though.

[K4SMX]

.....This is changing very soon though.
Additionally, somewhere I read that DirecTV was unhappy that a substantial percentage of "bad" LNB's returned were actually checking out as "good," so they didn't want them too readily available. We all know, however, that they do fail, and I'm sure not every single brand new one is perfect either.

[Halr]

Sorry not to respond, was not around a computer for the weekend. Thanks for all the replies!