wrote in message
...
In sci.physics Morse wrote:

wrote in message
...

Haven't looked at TV's in 20 or 30 years?


Well I have- I used to service them and still do occasionally. Turning
them
off at the mains does not cause loss of user settings or channels.

If the TV has a CRT, when it is "off", it will have low voltage applied
to the CRT filament to reduce the warm up time.


I can't say I've ever seen a modern TV that keeps the CRT heaters
running
while on standby, apart from a really ancient Pye B/W portable I once
came
across. It would cause a considerable reduction in CRT life for no valid
reason.

They don't run at full voltage when in standby.

Anything made in the past 10 years of so will have time functions,
local channel selections, and various other settings in RAM that all
go away if the set is unplugged.


Every modern TV I've seen holds channels and user settings in NVR and
they
aren't lost if you power it off. It's been about 20 years since I saw a
TV
which had volatile memory for the channel settings, and even then it was
backed up by internal NiCad button cells.

Except for the CRT, the same can be said of any recent DVD
or VHS
player, tuner/amp, or bread maker.


You're seriously saying that every time there's a power cut or you have
to
shut off the mains for any reason you have to readjust and retune your
TVs,
Videos, DVD players etc?

Yep, all the station/channel presets and all the clock/timer functions.

There is obviously cap backup on most of them since a short flicker
usually doesn't cause a reset.


Yeah, the manufacturer could have put in battery backup, but they
don't.


They don't need to- they use NVR (non-volatile RAM). Video recorders will
lose their clock settings (not their tuned stations) if powered off long
enough to flatten the battery backup or supercap, and some cheap ones
will
lose the clock setting instantly, but I've yet to see a modern TV or
tuner/amp which will lose stations if unplugged..

We have 8 TVs in our house and they have all been unplugged for prolonged
periods at one time or another. I've never had to retune any of them
since
buying them, nor have I had to readjust the user settings. The brands are
Philips, Sony, Toshiba, Samsung and Daewoo, ranging from around 150 quid
to
a 2000 quid RPTV.

Morse

I have 2 TV's, 2 VHS/DVD machines, 1 DVD machine, a tuner/amp, and a
bread machine of ages from 2 to about 20 years.

Every one of them goes to the factory defaults if the power is gone long
enough.

Either you are the luckiest guy in the world or there are regulations
in the UK that don't exist in the US.


I've crossposted this to sci.electronics.repair, maybe someone there can
shed some light on this.

Morse