Losing channels on a frequent basis

[longstockings]

Hi

I live in South Devon and I have a SKY+ (non HD) box with the larger size standard Sky dish that I setup myself.
The signal strength and quality is generally quite good but I'm frequently having problems with some channels in that I just can't receive them. This normally happens when there is something on that channel that I wish to watch.

The main problem channels include:

BBC 2
ITV
Channel 4
Five
BBC Three
Discovery Realtime
Discovery
Discovery Turbo
Animal Planet

At first I thought the problem was linked to the weather but it would appear not. During The Hotel which was aired on Channel 4 on Sundays about a Hotel in Torquay the picture would go at exactly 8:28pm every week. Coincidence perhaps but this makes me think that the problem is not a hardware fault but something wrong with the way I setup the dish.

Any help to fix this problem would be greatly appreciated as it is driving me nuts.

 

[Lazarus]

Can we assume that your Sky+ box is a Thomson .................... ??

You may well be suffering from a common problem afflicting those boxes (and others) : That of degraded Power Supply Smoothing Capacitors.

They are often manufactured with low quality components that last far too short a time - If you feel confident taking the covers off the box, you can visually inspect (keep your fingers out, even assuming you remember to disconnect from the Mains, as there can be a fair bit of stored energy around) for electrolyte leaks and/or (most likely) bulging of the capacitor cans.

 

[Analoguesat]

Yeah my immediate thought was power supply failure as well.

 

[longstockings]

Hi

Thanks for the help

It's a Pace box but as you say this could be suffering from the power supply problem.
I suppose if I hook up a fta box and try and watch BBC2 when it is unwatchable on Sky this may provide further clues. What is odd is that BBC 2 south west breaks up but BBC 2 Wales etc work okay.

 

[Analoguesat]

Hmm Pace's tend to be more reliable. Its worth popping the top off anyway and having a look at the capacitors in the power supply area. Keep your fingers well clear!

Another possibility is the cable from the dish has got damaged and its got water in it - different frequencies will be absorbed to differing amounts

 

[longstockings]

Hi

I think I should do some more testing. The second input signal sometimes drops off so this may be pointing to a problem with the cable as you said or with the lnb. Next time it happens I'll be more pro-active in tracking the problem down.

 

[PaulR]

What is odd is that BBC 2 south west breaks up but BBC 2 Wales etc work okay.

BBC 2
ITV
Channel 4
Five
BBC Three
...

It's almost deffo the power supply. There's no BBC2 SW but BBC2 England and all the channels in the first quote (I didn't check the Discovery channels I'm afraid) are all horizontally polarised and BBC2 Wales is vertically polarised.

The LNB is switched between the two polarities by voltage. V is selected by a nominal 13v supply and H is selected when the voltage is upped to a nominal 18v. When a power supply is on its way out it just can't supply the necessary voltage for the H channels.

So, unless there's something very strange with your downlead or you have a very fussy LNB, it's the power supply.

 

[Channel Hopper]

Before taking the lid off, try the receiver on just one incoming cable and set the receiver software as a single input unit.

If you get reception after this then it is the tuner and /or the motherboard that is at fault.

 

[longstockings]

Hi Guys

Here is an update. I tried re-aligning my minidish for the best signal possible. I used a digisat pro meter and noticed that the signal strength was far greater when I powered this device from a Dreambox 500 clone than from my Sky+ box which supported the theory that there was not enough power going to the lnb.
As a treat I have upgraded to Sky + HD but the new box though showing a much stronger signal than before still has the occasional problem with some channels.

Discovery
Discovery Turbo
Discovery Science
Nat Geo
Discovery Realtime
Crime Scene +1

and more.

I just tried to watch a repeated Wheeler Dealers episode and I am seeing no signal strength or signal quality on input 1
I flipped the cables around to see if that makes a difference but it hasn't and am toying with the idea of swapping out the quad lnb I am using for a different one but was unsure as to whether the fault could be related to it or whether I could try something else first.

Any help or advice would be appreciated. This is driving me nuts.

regards,
Richard

 

[Captain Jack]

Odd issue. I would have thought swapping the cables around would make a difference. I would replace the quad LNB - they are cheap as chips these days. Also, if possible try a new cable run.

 

[longstockings]

New LNB ordered. Fingers crossed it does the trick but if not the problem must be the cables themselves.