Televisions in standby mode

[BrenC]

Is there any definitive evidence that suggests it is inherently dangerous to leave a television in the "standby" mode? From my investigations it would seem that TV's are designed to be left in such a mode and that the only real fire danger is that an underlying fault would show up when the set is "on" and that could be at a time when it would not be detected e.g.when people are asleep. Any views on this subject would also be welcome.

[kurnal]

I look at it this way- and as always am happy to be corrected by those who know better.

Some equipment has a thermal fuse built in to the mains power supply - usually wound into a mains transformer - so that if it overheats the fuse cuts the supply. Usually these items are intended to be left connected all the time- and so often have a mains powered clock built in- radio alarms, videos, microwaves etc.
Other equipment constructed to a lower standard does not have a thermal fuse and this especilly includes all those appliances like ghetto blasters that have a black moulded figure of 8 connector on the plug in mains lead.

Back to the tv set- theres unlikely to be any thermal fuse or mains transformer for that matter. So in standby you are at the mercy of any electrical fault that may arise and give cause for arcing or short circuit. Switching the thing off greatly reduces the risk by reducing the number of components exposed to the mains supply and so reducing the odds of a problem arising whilst you sleep. Some TV sets haveknown problems- one model a few years ago was prone to carbonisation of the plastic of the on off switch with the normal arcing after repeated use, gradually leading to a continuous arc and a fire. This was not affected by being in standby or not.

So my advice would be turn it off - and for double the safety swich off the socket too.
All depends how much of a risk taker you are. And I must admit often what I say and do are two different things!

[John Webb]

Those sets with a mains input and a mains on/off switch should at the very least be turned off at the mains switch overnight and not left on standby. As kurnal says, this greatly reduces the number of components exposed to the mains.

Modern 'flat' eg LCD or plasma screen TVs, particularly the smaller ones, tend to have a completely separate power supply unit (PSU) from the set. The only connection into the set is a low-voltage (12 to 24V DC) connection. Even if this is disconnected the PSU remains on, although with little power being drawn from it the risk of a fault is probably low.