Intermittent picture and sound break-up Sony Bravia Android.

[Windblown]

We just bought a Sony Bravia 55" 4K TV. We are mostly satisfied with its performance, but have concerns with its behaviour when viewing via digital aerial in the 'TV' app. 

Most of the time we get really good reception and good  image and sound,  even on HD channels. We assume, therefore, that there is no problem with signal strength. Then, for no apparent reason, mostly when changing channel or just after switching on the TV, the picture breaks up and sound stutters in SD and HD. Waiting a few minutes, changing channel or restarting the TV fixes the problem. This is obviously unsatisfactory. We want a TV that works like a regular TV using a digital aerial signal when we want it to. 

Any ideas of what might be causing this or suggestions for fixing it?

Our set up includes a symmetrical 1Gb Ethernet connection and a 1TB SSD USB drive for recording TV programmes. Downloaded apps include Plex, Kodi, Express VPN (running only for Kodi) and  VLC. Firmware is up-to-date. 

[daveyh64]

Do you have another TV you can connect to the same aerial lead so you can determine whether it is the TV and not the aerial or the aerial connections.

Check the aerial connections/ plugs make sure the internal copper core is making good contact with its connecters.

Is your aerial on the roof or indoor.

If you have any HDMI cables going into theTV make sure the are kept away from the aerial capable as much as you can, poorly shielded HDMI cables can cause interference to the aerial signal.

Do you know the signal strength the 5 different multiplexes are being received at on your TV.

Multiplexes (mux) carry several TV channels and radio stations simultaneously.

For example all the HD channels are carried on 1 mux, select an HD channel then go to 

Settings> Help & Feedback> Help> Status & Diagnostics> Signal Diagnostics.

(the above path is for my XR42A90K Sony TV, your path may be the same, if not it should be broadly similar)

Note the Signal Strength and Signal Quality numbers.

Ideally signal strength should be about 80-90%, (100% is too high and can cause interference and picture break up).

If you have a signal strength of 100% you may need to buy a variable attenuator to dial down the signal strength.

Signal Quality should be 100%

You would do the same for all muxes, BBC1 SD, BBC2 SD, ITV SD and Ch4 SD are delivered on another mux,

select one of them and check the signal strength and quality.

To check other muxes switch to U & Dave, U & Drama for another mux and Quest for the last mux.

Checking the signal details at each stage.

Do you know which transmitter you are being served by, if so you can search for information on it and the muxes it broadcast and which channels are carried on each mux.

To determine which transmitter you should be receiving from then click on the link below,

https://www.freeview.co.uk/corporate/detailed-transmitter-information

If you are satisfied that the aerial, aerial connections and signal are in good order and compared with on another TV then it may be that your TV has a fault.

As it is a new TV and if under 30 days since purchase you are entitled to a new replacement or a full refund.

You need to contact the seller you got the TV from and see if they will send out a repair person to ascertain the fault (if there is one) and see if it can be repaired in situ.

[Windblown]

Thanks for your reply. I can answer  some of your questions straight away. Firstly, I know that the signal is not ideal. I am working to improve it, but I was puzzled why I should be getting a good HD reception whilst getting break up in SD. Some of your points might be answering my question. 

The issue is primarily on a particular spur from the roof aerial. The coax is high quality. It runs into the house then via a powered booster, where it splits into two - one branch to the Sony 4K TV and another into a Humax Aura 4K TV box in a different room serving a Samsung TV. The reason I have a powered booster is because up until a few days ago the spur split at a passive junction and I was having similar problems. 

The HDMI running from a PC adjacent to the Sony TV is a heavily shielded gold type, but is close to the aerial coax, but not touching,  because their sockets are close on the TV. 

Generally on signal tests throughout the house and on the spur in question signal strength is up to 90% and quality only 20%!  Today, following your instructions, signal strength 90/100%.  No reading for quality. The tool initially  suggested the channel was not available even though it was playing, but then after 5 minutes kicked in with a quality reading of 47%. (see image) 

Our transmitter is Sutton Coldfield (33km) . There are known variable issues in the area, i.e. a nearby tower block has mobile phone masts and microwave drums on it. 

I will repeat the diagnostic on other channels in different MUXs and report back later. 

[daveyh64 · Accepted solution]

Good you have two TVs in the house.

Have you swapped over the Sony and the Samsung to see if the Samsung suffers the same problem and can you compare its signal strength and quality with the Sony on the same aerial spur.

Does the Sonys problems disappear if the two TVs situations are swapped.

If the Samsung works without issue in the Sonys position with the Sonys aerial cable it could point to an issue with the Sony.

If the Samsung suffers from the same pixellation issues then it may point to a cabling and or connector problem.

If you check the signal on the Sony and scroll down further on the left to Network name does the name correspond to the broadcast area for the Sutton Coldfield transmitter.

It may be possible if there are two transmitters broadcasting in your area the Sony may have tuned to a different one to the Samsung.

In my situation I am in an area served by two transmitters, but my line of site due to buildings is better served by the furthest away transmitter (60kms), to make sure my Sony tunes in only to that transmitter I had to make a note of the 5 mux/ channels that this transmitter broadcasts and then do a manual channel search on the Sony for those muxes, ruling out any interference from the nearer transmitter with the inferior signal for my situation.

The point is to try and test and rule out any variables before we can decide if your new Sony TV has a physical problem.

Try even swapping over the aerial cables from the two set ups to see if it is a cabling issue (if length allows), please make sure the central copper core of the aerial cable is making good contact with the plug/ connector ensuring best service into theTV, if contact is not perfect then this can cause some muxes to have reduced quality, check both ends, out of the wall and into the TV. 

[Windblown]

I know there are signal issues, but my puzzlement was more to do with the variability of the TV's response., e.g. performing well in HD whilst pixelating in SD. 

Tomorrow, I am having an aerial specialist in to look at our signal quality/strength and then to make necessary changes.  I am going to put this thread on hold for a couple of days, then try swapping TVs around if the problem persists. 

[Windblown]

Hi,

So, aerial technicians have been in and found that the key booster junction box had pretty much failed and the 4G filter needed upgrading to include the 5G interference coming from a nearby tower block. All have been replaced and signals checked throughout the house. We now get 100% quality and between 60%-80% signal strength. That's ideal. 

Whatever was causing the Sony TV to be inconsistent has now no longer an issue. I guess it was trying to make the best of a poor situation. A rescan of channels has filled in any gaps that shouldn't be there and reception on SD and HD excellent.

Our transmitter is 30 km away, so I have ensured that only that one is used. The option to update saved channels is enables, but I have disabled the system's ability for search for other region's transmitters that occasionally reach this far. 

Thanks for your help and focussing my mind on the real issue.