Digital TV Signal Improves over Time

[2SPN]

I have a strange problem with my TV signal and I was hoping somehow out there could help. It is a scenario that a Google search doesn't really help with because (with my Google skills at least) I can't seem to word the search to get any specific answers.

I have a bog standard old plasma (!) TV with a bog standard aerial and aerial wall plate & fly lead. The TV worked fine until about a year ago when the signal started to fail regularly, we were never sure why and just stopped watching TV! I've finally decided to investigate further but after a couple of days of trying things, I am totally stumped.

The scenario is this - if I turn the TV on from standby, I have virtually no signal on any channels. After a few minutes ITV starts to appear then over a period of about 15-20 minutes the rest of the channels slowly improve too to the point where all the usual Freeview channels work fine. The signal isn't totally perfect - but largely watchable. If I put the TV on standby and then immediately turn it back on, the same thing happens but the channels appear to return more quickly.

I've changed the lead from wall to TV with a decent quality one and put in a new wall socket - but anything else is going to need significantly more effort as the coaxial from the aerial (in the loft) disappears under loft boards and somehow runs to the cavity wall.

Does anyone have any ideas as to what could cause this and what to try next? All help greatly appreciated!

[Road2Ruin]

Try another tv. The most likely cause is a faulty tv by the sounds of it. As it warms up, after turning on, it gets better.

[2SPN]

bks, that is the one thing we don't have! But you might well be right, many thanks for the idea. I'll try and find a friendly neighbour to do some tests...

(Edited to add that I used to own a TVR S3 too, had it for about 8 years)

Edited by 2SPN on Wednesday 9th October 21:50

[OldGermanHeaps]

borrow or buy a really cheap freeview box and plug it into your tvs hdmi port, that would narrow it down, and could be a permanent workaround if you dont want to change tv, with the added bonus of freeview hd channels, dont think any old plasmas had dvb t2 tuners in them.

[hornmeister]

If things improve over time then it tends to suggest heat build up and expansion improving a dodgy electrical contact.
Not a Sony TV is it? I was told by a TV engineer, that they had a reputation for dodgy solder joints a few years ago. I had one where half the screen would flicker unless I squeezed it's casing.

As already suggested an external video source like a free view decoder or even Fire stick will solve the issue if the problem is with the TV's internal tuner. In the long run it's probably too problematic and expensive to fix something which is likely to get worse over time.

[2SPN]

For completeness, I thought I'd post the outcome of this.

Following these replies, I looked into a USB/HDMI aerial connection, an aerial signal strength meter and just new aerial co-axial cable. Unplugging the previous cable in the loft seemed to have no effect on TV reception whatsoever which seemed to indicate that it wasn't connected. On the basis of that and that a new co-axial was the cheapest option AND on the assumption that I'd just pull the new cable up through the wall to replace the old one, I bought 25m of decent WF100 cable.

Bad idea - tried to pull the old cable up through the cavity wall and it snapped in the middle, ruling out using that route for ever more. I then spent about 5 hours routing the new cable across the loft, out of the fascia board and down a drainpipe before re-entering the property via a hole in the wall next to the TV. That meant I could directly connect the lead from the aerial to the back of the TV with nothing in between.

Now at least I'd ruled out any cable issues. So - turned the TV on, re-tuned all the channels and... - exactly the same. bks.

So, deciding to follow the advice above like I should have done in the first place, I dug out an old PVR with co-axial input but with an HDMI connection to the TV. Tried that with my new aerial, retuned and now I have all channels including HD, all working perfectly - proving that the problem was indeed with the aerial connection in the back of the LG plasma. For reference, it was an LG 50PK590 in case anyone else gets the same problem!

Many thanks for the responses.

[OldGermanHeaps]

Glad it worked.
you are doing really well with that thing still working, they were really bad for the y sus boards and power supplies failing and endless green sparklies.