There have been several threads on here regarding the issue of signal problems /break up / pixelation, 3 main causes could be :- 1) Cables – check they are in tightly and if possible check with a different hdmi cable

:- 2) Signal strength too high ! Causing the tuner to break up the signal – you can check strength in the channel and broadcast menu. If it’s constant at 100% signal it’s possible too high. – one suggestion is an Attenuator to reduce the signal (in my case it had no effect)

;- 3) Faulty unit. On certain channels I would get breakup after so long and get fluctuating quality readings. Another forum member came up with a test to replicate the fault.

havenview – 3 mnths ago  » 

There are numerous posts on several forums with regard to some poeple having issues with signal levels for the Humax Aura

There seems a strong voice from some that this is an HDMI issue but HDMI faults manifest very different traits than signal issues and I believe now I have found proof that these issues are FIRMWARE related and I would like to invite members to try out some tests to add weight to my findings

My signal issues manifest themselves only on certain muxes and they are “reliably faulty” in that I can tune to a channel and within a few minutes be guaranteed of viewing picture block freezes, audio pops and several seconds of I/B/P frame blocking.

My antenna system is good and I have checked using 2 aerials and confirmed good signal AND acceptable levels to muliple other boxes so I was sure this was NOT a signal related issue. I experience good level and quality readings from the built in signal testfor some muxes but on the faulty ones the quality jumps from 100% down to as low as 40% in an erratic manner

I also noted that there seemed to be an improvement when the box was restarted but only for a limited period – indeed other users have also posted on this too

Then it finally clicked – the issue happens as a consequence of CHANGING channel – the testing procedure is this

1. Tune to a faulty channel and observe the picture/sound break up

2. Issue a reboot – I use the freeview button and cursor all the way over to the right to the power icon and choose restart

3. Wait for the box to restart – the previous faulty channel should be the default tuned channel – DO NOT CHANGE CHANNEL

4. Observe if there is any break up – in my case at this point the picture and sound stability has always been A1

5. Now change channel to a different mux (an easy bet would be to go between an SD and an HD channel) and then return to the original suspect channel

6. For me the break up and distortion starts happening almost immediately

7. Reboot and all comes good

In my system the worst channels always seem to be on COM5 (Winter Hill) so I’ve been checking using Sky Arts on channel 11. I tuned and rebooted to that Yesterday morning and left it alone and not changed channel. It has been rock solid every time I have checked – even with other channels recording. I have just changed channels now and straight away I get the picture and sound break up return

I would be interested if other users who have experienced this issue could also try this as a means of wider testing

I can say after reporting the issue and several communications with humax they replaced my box and 6 months later I haven’t had any more issues.

I get similar issues with the SD BBC channels. They break up/black screen.

HD channels are fine. Didn’t happen with my older Freeview box (YouView)

AceGrace – 1 hour ago  » 

I get similar issues with the SD BBC channels.

What is the signal strength and quality when tuned to BBC1? (Press Settings icon > Channel & Broadcast> Signal Test).

AceGrace – 1 hour ago  » 

It flicks back and forth between 66% and 14% but says no signal on the screen. Sometimes I get a picture and it glitches a lot.

Happens only on all the bbc, itv and ch4/ch5 sd channels. The HD ones are perfect.

I know that there are a few competing transmitters but my aerial is pointing to Brighton, but when I had a Youview box, it was all fine.

There is more than one possible explanation. Lets start with the easy one. Tune to BBC1 SD and repeat the signal test to the right of Tuner 1 you will see a line of letters and numbers; it should start “CH”, please tell us the number after “CH”. Then change channel to ITV and repeat the signal test, again tell us the number after “CH”. If possible could you give us the first part of your postcode.

My personal findings are that the Aura does seem to have sensitive tuners in some signal situations. I do know, having had communication with Humax, that they are different to their previous models. I had a 5000T and had no issues apart from too much signal causing pixilation which I fixed with an attenuator. The Aura was a direct swap for the 5000T so I expected that the existing TV signal distribution would work. I am 14.3 miles from the nearest main transmitter with a clear line of sight. There are two other main transmitters, one at 35 miles (22 degrees different) and the other 61 miles (142 degrees different)

My symptoms have been brief pixilation events (2 to 3 seconds) on HD channels. Signal wise I did have 100% quality and 100% strength on BBC1HD. I throttled this back to around 90% strength with an attenuator but could not go any further as Channel 55 (COM7) dropped off as it is transmitted at much lower power.

After a lot of research, and evaluation of a second test Aura unit supplied by Humax, I came to the conclusion it must be something in the signal reception path upsetting the Aura.

What finally seems to have fixed it for me was changing the aerial which is loft mounted. My original was a SLX Digidome omni-directional which went in to a powered Labgear distribution, this created a lot of signal boost (which was fine before analogue was switched off) so I originally removed the Labgear powered distribution, thinking reducing the boost would fix it, but this made no difference. As the SLX is Omni-directional I was also concerned about potential interference from the other transmitters and any other sources hence the decision to try a new aerial.

I now have a Labgear 27885 Log-periodic aerial which is powered as it is still loft mounted. Log-periodic aerials are highly directional and have more constant characteristics over the frequency range, they are also a lot less prone to reflection interference. So far in 3 weeks I have not observed a single picture issue (I was seeing 4 or 5 a week on recordings) and the signal strength across all channels is much more consistent even on Channel 55 (COM7).

From all my research finding the optimal set-up can be complicated and depends on many factors. For instance, a lot of installations have inappropriate aerials from when analogue was still being transmitted and digital was on much lower power and lots of high gain antenna were fitted. Another factor can be older Yagi aerials in the wrong group which can just pick up the local signal or a fringe one.

My conclusion is that the Aura is not always to blame, it looks as if my signal reception kit was and, in the past, I might have just got away with it.

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Martin Liddle – 17 hours ago  » 

Sorry I used an arbitrary BN14 postcode but that shows me that coverage in your location isn’t straightforward.

OK I have now received the full postcode by PM and it does look as though the local transmitter (described as Whitehawk Hill by the Freeview Coverage Checker) should give good reception. Two provisos: it is a low power transmitter 4kW (as opposed to 200kW) so might be more susceptible to interference and secondly the Aura seems to have its tuning mixed up. BBC1 on multiplex channel 24 is probably from Rowridge whereas ITV on multiplex channel 35 is from Whitehawk Hill. My suggestion is that you try another automatic channel search then select BBC One (LCN 1) and do a signal test and see if the multiplex channel is 48, repeat for ITV (LCN 3) should be 35, Sky Arts (LCN 11) should be 34, Quest (LCN 12) should be 32, Yesterday (LCN 26) should be 33, BBC One HD (LCN 101) should be 36. If any of the values are wrong, the next step would be a manual tune.

I will give that a try thank you.

How do you do manual tune of those channels specifically?

The automatic tuning is OK for the majority of the channels.