Diagnose Faulty Quattro LNB - How To Test?

[KillingTime]

Hi,

Lost satellite reception yesterday. Both tuners on a single box. 0db signal both tuners. Plugged in another receiver, no reception so it's either the LNB or switch or the dish has been moved.

Not had any windy weather. Checked the power supply on the switch, OK. Sat box is working as I can play HDD movies on it.

Other than just replacing the quattro LNB, is there any way to test it?

I tried putting a satellite meter in between the LNB and switch to see if it was outputting anything and got nothing but there's no DC voltage output on the switch to the LNB, like there would be with just a regular single port LNB (13/19v), so there's nothing to power the meter (it didn't light up).

One other thing, I put a DVM on the sat input of my normal receiver and didn't get any DC voltage either while on the 'Signal Finder' menu. I do get 13v on the 'backup' receiver.

Could be looking at multiple failures here.

Thanks.

 

[jeallen01]

I would have thought you might simply bypass the switch and so connect the receiver directly to the LNB, 1 LNB port at a time - have you tried that yet?

 

[scopus]

Hi,

Lost satellite reception yesterday. Both tuners on a single box. 0db signal both tuners. Plugged in another receiver, no reception so it's either the LNB or switch or the dish has been moved.

Not had any windy weather. Checked the power supply on the switch, OK. Sat box is working as I can play HDD movies on it.

Other than just replacing the quattro LNB, is there any way to test it?

I tried putting a satellite meter in between the LNB and switch to see if it was outputting anything and got nothing but there's no DC voltage output on the switch to the LNB, like there would be with just a regular single port LNB (13/19v), so there's nothing to power the meter (it didn't light up).

One other thing, I put a DVM on the sat input of my normal receiver and didn't get any DC voltage either while on the 'Signal Finder' menu. I do get 13v on the 'backup' receiver.

Could be looking at multiple failures here.

Thanks.

Have you checked the multiswitch is it powered up? Any power lights?
Take a receiver outside. Remove say, the vertical low lead from the LNB, plug another flylead straight into the back of the receiver from the LNB, select a V/L channel on the receiver see if you get a picture, if not possibly the LNB gone. If yes, possibly the Multiswitch gone. But could be as simple as the dish has moved..

 

[KillingTime]

The switch is powered up, a LED lights on it. Even tried a different power supply.

I've not tried bypassing the switch yet, but I'll do that next.

Does anyone know which band and polarization old (1990's) sat boxes look to when deciding if there is a signal on power up? I get a 'No signal found / cable disconnected' on the backup sky box and that's it. It's looking for a particular channel but I don't know which one, so I don't know if it's Low/H, High/H, Low/V, High/V.

Thanks.

 

[KillingTime]

The switch is powered up, a LED lights on it. Even tried a different power supply.

I've not tried bypassing the switch yet, but I'll do that next.

Does anyone know which band and polarization old (1990's) sat boxes look to when deciding if there is a signal on power up? I get a 'No signal found / cable disconnected' on the backup sky box and that's it. It's looking for a particular channel but I don't know which one, so I don't know if it's Low/H, High/H, Low/V, High/V.

Thanks.

OK. bypassed the switch and connected HV to the receiver. Tuned to Yesterday channel (12129 V) and got nothing. Signal strength was 0. Hooked the backup receiver up and couldn't find Yesterday in the listing, but the box setup reported 0 signal strength as well.

Does anyone know how the signal strength meters work on sat boxes? Is it really dBm at the receiver, or something more clever like it's looking for a certain channel \ frequency \ polarisation before taking a dBm reading?

None of this tells me if the LNB is actually the problem, the dish could be off for some reason, which brings me back to the question, how do you test a quattro LNB?

Thanks.

 

[Mickha]

I don't understand why you're using a Quattro LNB, unless you have your signal distributed to many rooms.
You haven't posted make/model of your satellite receiver, but at least we now know that you're dish seems to be static, and pointing to 28.3E.
Have you checked your receiver on a different dish, friends, or family, to confirm that your receiver is fine?
How old is your LNB?
Did you set this system up yourself?
You could try all 4 differnet outputs, on your LNB, to see if it has partly failed, try the Horizontal low option.

 

[Channel Hopper]

Hi,

Lost satellite reception yesterday. Both tuners on a single box. 0db signal both tuners. Plugged in another receiver, no reception so it's either the LNB or switch or the dish has been moved.

Not had any windy weather. Checked the power supply on the switch, OK. Sat box is working as I can play HDD movies on it.

Other than just replacing the quattro LNB, is there any way to test it?

I tried putting a satellite meter in between the LNB and switch to see if it was outputting anything and got nothing but there's no DC voltage output on the switch to the LNB, like there would be with just a regular single port LNB (13/19v), so there's nothing to power the meter (it didn't light up).

One other thing, I put a DVM on the sat input of my normal receiver and didn't get any DC voltage either while on the 'Signal Finder' menu. I do get 13v on the 'backup' receiver.

Could be looking at multiple failures here.

Thanks.

What make/model is the LNB ?

 

[KillingTime]

.

 

[KillingTime]

I don't understand why you're using a Quattro LNB, unless you have your signal distributed to many rooms.
You haven't posted make/model of your satellite receiver, but at least we now know that you're dish seems to be static, and pointing to 28.3E.
Have you checked your receiver on a different dish, friends, or family, to confirm that your receiver is fine?
How old is your LNB?
Did you set this system up yourself?
You could try all 4 differnet outputs, on your LNB, to see if it has partly failed, try the Horizontal low option.

>>I don't understand why you're using a Quattro LNB, unless you have your signal distributed to many rooms.
12 outputs to sockets around the house.
>>You haven't posted make/model of your satellite receiver,
Zagema H7S
>>How old is your LNB?
About 10 years old.
>>Did you set this system up yourself?
Yes. Years ago.
>>Have you checked your receiver on a different dish, friends, or family, to confirm that your receiver is fine?
No. No one close.
>>You could try all 4 different outputs, on your LNB, to see if it has partly failed, try the Horizontal low option.
Try them how?

 

[KillingTime]

What make/model is the LNB ?

Don't know. Sorry. I'd have to climb a ladder and look.

 

[Channel Hopper]

Can you take a picture from the ground ?

 

[KillingTime]

Can you take a picture from the ground ?

Have to wait for it to stop raining. It's chucking it down ATM. I don't see how a picture is going to tell me if it's broken though.

To put the question another way, when a satellite guy/company comes out to diagnose the problem, how does he test a quattro LNB?

1. Can you power up a quattro LNB up with only 1 connection instead of 4, with a regular 1 port receiver?
2. Does it need all 4 connections hooked up to a switch?
3. Do all 4 connections need 13v or some other voltage to power the LNB?
4. Is there a special quattro LNB test device?

Can't find anything written on this. The web is just full of people selling them.

Perhaps they don't test them, and just replace stuff one box at a time until things work again.

 

[jeallen01]

FAIK, each of the LNB's in a quatro is just an independant LNB unit which can only receive signals that are H or V, and Low or High in the Ku band - thus you have 4 entirely separate LNB's that can receive only one of those four combinations. As such, I assume that each is powered solely from the cable that is connected to it.

 

[scopus]

The switch is powered up, a LED lights on it. Even tried a different power supply.

I've not tried bypassing the switch yet, but I'll do that next.

Does anyone know which band and polarization old (1990's) sat boxes look to when deciding if there is a signal on power up? I get a 'No signal found / cable disconnected' on the backup sky box and that's it. It's looking for a particular channel but I don't know which one, so I don't know if it's Low/H, High/H, Low/V, High/V.

Thanks.

Press the info button, that should tell you the frequency and polarisation. Or look on Flysat that will tell you what the parameters are..

 

[a33]

1. Can you power up a quattro LNB up with only 1 connection instead of 4, with a regular 1 port receiver?
2. Does it need all 4 connections hooked up to a switch?
3. Do all 4 connections need 13v or some other voltage to power the LNB?

Many quatro LNBs can be powered by ANY port. However, there are quatro LNBs that expect to be powered by one specific port.

Did you check (with a multimeter) that power reaches the LNB? If not, there either is a fault in receiver or cable or multiswitch, or the receiver might be in protective mode due to a prior short-circuit (it might need a cold restart, to counteract that).
When no power reaches the LNB, also try to bypass the multiswitch, as indicated before.

Often (but not with all receivers), a signal strength of zero indicates a cut in the power circuit.

I would first check if voltage is present in the circuit; and only after that check other things.

Greetz,
A33

 

[Mickha]

Most of us don't use professional distribution systems, that require a Quattro LNB, and distribution switch, these are generally for Hotels, Appartment blocks, or very big houses, where you want to run a signal to more than 4 rooms.

I should imagine that the switch is in the attic, or other location, in the buiding. If you have access to it, and it is just your house, then you can by-pass the switch, and connect the cables together, using a F connector joiner:


This connects the two F Connectors, one from the LNB, directly to your receiver, by-passing the switch, allowing you to test all 4 ports, Horizontal High/Low, and Vertical High/Low.

After 10 years there's a good chance anything could have failed, the LNB trough water ingress, and general wear, the external cabling could have become damaged, the dish might have moved, or the switch failed, due to anything from age, lightning strike, or water, if in an attic, or location that suffers from moisture, water ingress, or if by the sea, the corrosive problem with salt water.
In most cases the LNB will eventually fail, and require changing, but in your case it might be worth contacting a professional satellite engineer, and paying to have the system checked. Of course, if this is an appartment block, or multiple flats, then other users, of the system, would be experiencing the same problem, and it's up to the owner, to repair it.

All this is guess work, because we still don't know your situation.

If you do own the building, and have had cables run to 12 outputs, have you checked other rooms, in the house?

 

[Channel Hopper]

Many quatro LNBs can be powered by ANY port. However, there are quatro LNBs that expect to be powered by one specific port.

Did you check (with a multimeter) that power reaches the LNB? If not, there either is a fault in receiver or cable or multiswitch, or the receiver might be in protective mode due to a prior short-circuit (it might need a cold restart, to counteract that).
When no power reaches the LNB, also try to bypass the multiswitch, as indicated before.

Often (but not with all receivers), a signal strength of zero indicates a cut in the power circuit.

I would first check if voltage is present in the circuit; and only after that check other things.

Greetz,
A33

The second reason I asked for a picture is to find if the LNB is actually a quattro model, or a humble quad that just happens to be switched correctly by the switch indoors.

 

[KillingTime]

Evening All,

After some more fault finding, I found the problem; the LNB, pictured. Looks like the hole let water in and that finished off the electronics. Should have looked at this right after testing the power supplies but it was raining & didn't want to go up the ladders.

The hole was a giveaway, but to answer my original question I found a way to test the LNB before getting a new one and can confirm the video method below does work with just one cable on a quattro. It will therefore also work on single, duals and quads. Tried the method on the new quattro LNB and the dead one. Some meter deviation on the working one, and no deviation on the dead one. My sat meter has an audible tone, and it's easier to hear the tone change than see the needle move.

Picture of the new LNB installed at the 7 PM position for Astra2. Added some coloured tape & heat shrink to make IDing the cables easier, and heat shrunk over the F connectors before pulling the guard down to keep the weather out.

The above method only works if your receiver outputs 13/18 volts on the satellite cable. If it doesn't then the sat finder meter will not light up and you will not get a tone. You can also test the voltage by putting a straight paper clip in the receiver F port and measuring the voltage to chassis with a multi-meter.

My Zagema H7S (Enigma2) was doing something weird with the receiver ports. No voltage at all on any ports after the tune failed because it couldn't find a signal. Thought the receivers had blown. I only got a DC voltage when I was in the Signal Finder menu *and* I had the correct receiver port selected. This was my original problem - didn't spot the menu to select the correct port. You can also select different transponders as well and that changes the voltage (13/18) depending on the polarisation, but all voltages will work with a sat finder meter. My old Panasonic DSB30 (now 22 years old) seems to output 19v even when in standby mode by comparison.

Don't know what make the old LNB was. The weather has removed the ID sticker, but it was a quattro because I remember buying it. Glad it's not my switch (also pictured). Paragon seem to have gone out of business. Their website is up for sale and all their product documents have gone with it.

Thanks for the replies.

 

[jeallen01]

"Times have changed" a lot in the last few years for the satellite kit market - many manufacturers have simply "shut up shop" (and many retailers, especially in the UK have done the same) or "jumped ship" to other areas of technology. Sometimes the only way to try to replace old kit "like for like" is to look at what's available on the used/secondhand markets.