Wavy Picture problem

Yeldarb1967

New Member
My PVR which is 3 years old and which I have had no problems previously has suddenly developed a wavy picture on both live TV (all channels) and also recorded TV ( I know the original recording was ok).
Does anyone know what might be the problem and if their is a fix or should I just bin it and buy the latest model.
Hope someone can help.
 
Surely only getting 'wavy' output if via an analogue output. Is this connected by SCART cable - is it horizontal lines, picture distorting, or what? If you have a HDR can you connect it with HDMI?
 
A faulty PSU can cause all sorts of problems. I'm with EP on this one.
Open the case and look for swollen/leaking capacitors on the PSU board. (Disconnect from mains first. Health and safety brief over.) Search the forum for capacitors. There's loads of stuff about them here and it seems like a fairly common fault on STBs in general. They seem to use low quality electrolytic capacitors which seem to leak/go faulty after about 3 years.
@dragon-it. Even if connecting it by HDMI fixes it, there is still an underlying fault which I bet £5 is the PSU caps.
 
My PVR which is 3 years old and which I have had no problems previously has suddenly developed a wavy picture on both live TV (all channels) and also recorded TV ( I know the original recording was ok).
Does anyone know what might be the problem and if their is a fix or should I just bin it and buy the latest model.
Hope someone can help.
I think we need to see what this "wavy" picture actually looks like. Please take a photo and post it, and also confirm the problem does not occur when using the TV's internal tuner or another video source (eg a DVD player). State whether the HDR-FOX is connected to the TV by SCART, phono, or HDMI.
 
Agreed quite possibly PSU but also quite possible dodgy SCART cable or where it is routed next to etc... like Black Hole says a) show us what it is link, b) elimate possibilities, i.e. is it just HDR doing it, and does it do it with a different known good cable or input on the TV, or even a different TV/location.
 
It's hard to see how a dodgy PSU in the Humax can cause what I would describe as a "wavy" picture on the TV over a digital interface (or even an analogue one). A dodgy PSU in an analogue TV - maybe.

The OP has so far provided too little information to jump to any conclusion or even half a suspicion, so let's wait for more data.
 
Hi everyone, thanks for suggestions. I have done some further investigation and have found that:

I have just connected a TV direct to the PVR and it works ok on both live and recorded tv.
I perhaps should have said previously that my house is Ethernet cabled and the tv (several) are connected to the Humax box via the cat5.
I live in a 3 storey house and it was pre cabled when I bought it new 10 years ago.
Everything goes via a patch panel. Telephones, computer, Humax / tv.

It looks like Ezra might have hit the button, but what are the likely causes of electrical interference. The computer and telephones are all ok
 
Ok so what are you putting over the Cat 5 - analogue video from SCART to Cat5 adaptor both ends then, or HDMI to Cat5 both ends?
 
Hi everyone, thanks for suggestions. I have done some further investigation and have found that:

I have just connected a TV direct to the PVR and it works ok on both live and recorded tv.
So to clarify, there is nothing wrong with the hummy itself, it's an infrastructure problem.
 
You still need to clarify (in some detail), how the Video gets from your Humax to your TV, i.e. Questions in #9
 
Agreed - first reaction is "how the heck"... second reaction is "must be sending analogue video over cable that is not suited". There are better ways of doing it.
 
Sorry I thought I had replied to that question.
Digital signal from a communal aerial into PVR. (That's ok as have checked a TV direct from PVR via scarts straight into a TV.) Signal is then Out via a scart into the patch panel then via Cat5 through the house. Then from wall socket into TV via another Scart.

Have checked TV working ok by running a DVD into it direct.
 
First off, the signal from the aerial is not digital, it's analogue UHF modulated with a digital signal. Second, feeding analogue video into a length of Cat5 (four twisted-pair cables in an overall sheath, not necessarily with an overall screen, and with potentially other signals on other pairs) is no way to treat a signal.

The way to watch recordings from the HDR-FOX on remote TVs around the house is by DLNA (a network service), although this requires a "smart" TV or an auxiliary box (eg a computer of some sort, preferably with HDMI output to the TV). The HD-FOX is the box of choice, but these are now all but unobtainable and some people have had success with a Raspberry Pi. This solution provides full resolution playback of the recordings, although obviously not live TV (I take it you can't route an aerial to the actual TVs).

Failing that, run proper video signal cable (some people are using 15m analogue links), or there are devices available to adapt the HDMI signal into a Cat5 distribution and then recover it at the other end - HDMI will obviously provide full resolution, and can be "split" using a matrix switch to feed multiple destinations.

How are you sending commands to the HDR-FOX from the remote location?

Sorry I thought I had replied to that question.
Nope - not in a way that we would understand anyway. What you are doing is unconventional to say the least.
 
Well then there is interference from the cabling somewhere... try unpatching other things one by one, e.g. wifi routers, other video signals etc.

Also could be the scart to cat5 adapter. Try two adaptors, a cat5 patch cable into the back of tv perhaps...

Or if you want to get fancier and use hdmi over cat5 instead, especially if you have a HD TV and fancy patching is silly to downgrade to analogue SCART video to watch at SD resolution.

http://cpc.farnell.com/pro-signal/p...n_merch=Featured Products&MER=e-bb45-00001001

Steve
 
Signal is then Out via a scart into the patch panel then via Cat5 through the house. Then from wall socket into TV via another Scart.
As far as I can see there is no Analogue to Digital / Digital to Analogue conversion in this path at all so you are effectively just using a very long SCART Cable via the 4 available twisted pairs (3 for RGB and 1 for audio) or a single twisted pair for Composite video plus 1 or 2 twisted pairs for audio, this will be very prone to picking up mains noise which I suspect is what is happening, especially if the CAT5 cables being used are running alongside other cables carrying mains power or other digital signals
 
Hi Everyone. Thanks for all the advice, it has certainly helped me focus on issues. You will no doubt gather I am not very techy. However I have been using this system for 10 years and it has worked fine. Picture quality and sound are both good 'normally'. This only happened on Friday night. Friday am it was fine. Nothing has changed in the house, my wife is still here. Which to my mind means something somewhere has developed an electrical fault. I will keep trying to eliminate things.
 
Who was it I owe a deep sea diver to? Answers on a postcard please to the usual address.
 
I have been using this system for 10 years and it has worked fine.
By the skin of its teeth. The slightest disturbance could send it off-par, even something your neighbours do (depending on proximity) or (for example) a change to the mobile phone network.

Picture quality and sound are both good 'normally'.
Compared with what? What kind of TVs are you using as displays? Yes, on a 625-line CRT TV you probably wouldn't notice the difference, but compared with an HDMI connection to a half-decent 1080-line flat panel TV you wouldn't want to go back. It all depends what you're used to, and you are certainly not benefiting from the HiDef services (the analogue output from the Humax is 576-lines). A good analogue connection provides a picture quality I would describe as passable or OK, definitely not "good".

You will no doubt gather I am not very techy.
You still have not provided the detail of your setup (I'm sure we are all interested). How, for example, is your patch panel made? What have you used to adapt the screened stereo audio and video signals from SCART or phono into the twisted pairs of Cat5? Is the Cat5 shielded or unshielded, and is the shield grounded anywhere? Do you have any buffer amplifiers or impedance converters?

Transmission lines (the technical term for a cable designed to carry a high-frequency signal any distance) have a specific characteristic called "impedance". Although the conductors have minuscule resistance, the combination of inductance and the capacitance between the send and return conductors (the wires in each pair of a twisted pair, or the core and screen of a coaxial cable) creates an impedance which defines how the transmission of a signal is affected by joints in the signal path.

If you can imagine a wave passing along a trough of water, everything is fine until the wave meets a discontinuity in the trough - and then some of the wave carries on past the discontinuity and some of it bounces back. The same thing happens in transmission lines. The output from the Humax should be designed to drive a cable with a specific impedance, the input to the TV has the same impedance, and if all the cable and connectors between the two have the same impedance all will be well (apart from loss of signal due to distance, and the possibility of interfering signals if the transmission line is inadequately screened).

However, the output from the Humax is probably not matched - which does not matter if the rest of the transmission system is matched to the TV input. If there is a discontinuity though (a place where the characteristic impedances on either side of the joint do not match), some of the signal will be reflected back, and the reflected signal will be reflected forward again from another discontinuity (eg the output connector at the Humax), and when dealing with the high frequencies of a video signal (the colour sub-carrier is 4.43MHz) the reflected signals interfere with the main signal and degrade it. I don't know the impedance of the signal pairs in Cat5 off the top of my head, but maybe - just maybe - they are compatible with the impedance of the video system. Twisted pairs are what we call "balanced line" though, and ideally require a different drive from the single core of a coax cable.

If you are using modern flat-panel HD TVs with HDMI inputs, I recommend you enter the 21st century and look at distributing the HDMI signal from the Humax. There are adapters to launch HDMI into Cat5, or boosters to extend HDMI several tens of metres (I have a 15m HDMI link out of my matrix switch). If properly designed in, Cat5 is capable of very good performance in the right situation.

You still have not mentioned how you control the Humax from elsewhere - we may be able to offer you some tips on that.
 
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