There are three reasons for there being no picture when the box is in standby

1/ There is no aerial link lead from box to TV so the TV's internal Freeview won't work
2/ There is a link lead but you "forget" to switch to the TVs internal Freeview (known in the trade as finger trouble )
3/ The box has a low power standby mode. In this mode it turns off the little internal amplifier that splits the aerial signal between the boxes tuners and the socket out to the TV. Hence no signal. Not entirely sure why manufacturers do that, unless they cannot conceive of any situation where a user would not want to watch telly using the box? Anyway most such boxes have a menu setting to turn low power stand-by off so this amplifier stays alive when the box is in standby so you can watch telly still.

It's a requirement of EEC law that new kit must have a standby power mode of less than 0.5W (was 0.75W). To achieve this all kit not required to allow the box to wake from sby is disabled including the rf loop amplifier and the clock display. For 99.99% simply fitting a decent uhf splitter will allow retention of low power sby mode.

I wonder though how many boxes get returned as "faulty" because the user puts it into standby and the picture on the telly dies even though they are using the TV's tuner?

Or how many boxes get left on 24/7 for much the same reason. Or how many discover the Low Power OFF setting and turn it off. Either way defeating the purpose of the regulation in the first place.

You and I may be able to bypass the RF loopthrough but I wonder how many less technically aware people out there would?

By law all AV kit sold in the EEC since December 2009 must have a low power sby mode (1W in 2009 reduced to 0.5W Dec 2012). The numbers sold must run into millions, I rather think you exagerate the impact somewhat.

In any case you wondered why manafacturers provide low power sby. The fact is that they have to do so, the regulation is mandatory thoroughout the eec.

(VERY DEEP BREATH!!) ...

Anything tech or electrical is a major problem for me..
I'm trembling at the thought!
I know..I know... you are all thinking..what a wuss!

Quite frankly I pay £30 each time for a gent to come in and sort out minor (according to others) probs on my computer rather than tackle it myself as I just end up getting into more and more difficulties...

However, I shall have a go tomorrow when I have plenty of time to think about it first! .. : .. Lots to digest there folks.. will report back later.

It's three cables: power, aerial, and HDMI (to the TV). Keep Calm and Carry On!

Stupid higgerant Eurocrats who don't understand the consequences of their decisions. I want RF and SCART pass through, thank you very much. Why don't they just ban electrical equipment and make us sing round the joanna?
Passive splitters intruduce losses; powered splitters defeat the purpose.

Sorry completely and 100% ignorance about how digital transmission works. It's you are the stupid one. Yes passive splitter introduce losses, the whole point of digital is that that signal level is largely irrelevant between vary large variations, all that is required is that the tuner decoding the signal can decide what is a zero and what is a one. The signal level means precisely nothing. The capability to distinguish between zero and one is measured by the quality, the whole point of digital is that provided that you can tell a 0 bit from a one then reception is 100%.

Your post is complete gibberish and frankly shows you have no absolutely no understanding of the advantages/disadvantages of digital transmission

If you want to pass through analogue scart video connection from say vcr scart to TV scart with the transfer box unpowered then this needs no power merely a connection from vcr scart in to TV scart out. Nothing to do with this discussion at all

Any reduction in signal level will increase the chance that electrical interference will wipe out the signal, e.g. an unsuppressed lawnmower next door.

I've checked my Panasonic DVDR and the instructions say that power saving mode stops the AV passthrough working. I suspect that other boxes are the same.

This is the case in all the A/V devices with a low power standby feature in my experience. Also most SCART pass through circuits include a low gain amplifier to compensate (some times over compensate) for the loss of signal needed to feed the devices tuner(s). The loss of power to this amplifier in LP mode would degrade to feed through signal even if the circuit enabled the signal to be fed through at all. I suppose it is credible that the feed to the tuners could present a sufficiently large input impedance to have insignificant impact on the signal in LP mode but I doubt it.

Colin

Yes that is CORRECT...

Think about asking a friend for some tuition to increase your confidence: those £30s will keep adding up otherwise.

"Quite frankly I pay £30 each time for a gent to come in..."

Could be the start of a wonderful relationship.

Yes!! I like it..I like it!!

On a more serious note..
Thought I would just update y'all..
I waited till my home help/cleaner lady came in as the box is quite heavy and where it is positioned it is very low down which proved to be too much for me with my bad back...
However..today, between the two of us we got it all installed and it is going fine! ..YAY!!

Thanks very much for all your input and advice...