Leave your TV on

[snopes]

Comment: I have heard (somewhere?) that leaving a television on all the
time is "good" for it, and will make it last longer.

[Jay Temple]

I've never heard that. However, whenever my dad bought a new TV, he'd leave it on for the few days, turning the sound off at night, so that certain problems would be likely to occur right away, while it was still under warranty.

[Silas Sparkhammer]

Partly true... With electronics...just as with light bulbs...the greatest stress comes during powering-up. A light bulb is most likely to burn out when first turned on...and the same is true for tvs, radios, computers, etc.

However...constant running produces a constant low-level stress on the system. So, for any electronic device, there is a "breakeven point." No one knows exactly what this is! I've heard several rules-of-thumb, from half an hour to two hours.

Also: most modern tvs have a trickle charge running through them while powered off. Pushing the "off button" is not the same as pulling out the wall plug. So...don't control the tv from a power outlet that is turned off and on.

(At my workplace, there is a database server that has not been fully powered off for over six years. The manufacturer has all but guaranteed us that, if we ever do turn it all the way off, that it will not start up again! At least a few of the components, on average, are expected to fail after so long a period without a power cycle. So, for health of your machines, do a "120 bounce" at least once every couple of months!)

Silas

[matches]

I doubt it would make your t.v. last longer, it might keep your on off knob from falling off if t.v.s still had on of knobs.

The chemicals on the inside of the tube will eventually wear down, so in that sense the more the tube is used the shorter it will last.

Legends like this usually require some notion of a power surge when you first power up the item. It could have been true in the past, but modern televisions, just like modern computers and automobiles are simply better designed than that.

I could see some old model from the 50's having such a problem, but i would think a modern television would have its own surge protection devices already installed.

[diddy]

However...constant running produces a constant low-level stress on the system. So, for any electronic device, there is a "breakeven point." No one knows exactly what this is! I've heard several rules-of-thumb, from half an hour to two hours.

For real older devices, maybe. But most devices nowadays have a very low break even point thats actually quite easy to measure. A recent Mythbusters episode on light switches on or off. Grant determined that the break even point on most bulbs were less than a second.

[Troberg]

Partly true... With electronics...just as with light bulbs...the greatest stress comes during powering-up. A light bulb is most likely to burn out when first turned on...and the same is true for tvs, radios, computers, etc.

However...constant running produces a constant low-level stress on the system. So, for any electronic device, there is a "breakeven point." No one knows exactly what this is! I've heard several rules-of-thumb, from half an hour to two hours.

Exactly. In practice, it doesn't matter anyway, as the TV will be old and replaced by the time it breaks anyway. Electronics today is outdated long before its life span runs out.

At my workplace, there is a database server that has not been fully powered off for over six years. The manufacturer has all but guaranteed us that, if we ever do turn it all the way off, that it will not start up again!

Sound like one of my servers. I'm scared as hell of restarting it, as it usually takes ten tries (at least) for it to start up again. Still, not much that I can do, it's such an odd combination of hardware (dual Celerons on a slotted P3 board) that a new motherboard, which is the failing component, is hard to find.

For real older devices, maybe. But most devices nowadays have a very low break even point thats actually quite easy to measure. A recent Mythbusters episode on light switches on or off. Grant determined that the break even point on most bulbs were less than a second.

That had nothing to do with life span, it was power consumption.

[diddy]

That had nothing to do with life span, it was power consumption.

Never said anything about that. I was merely pointing out about break-even times. I'm well aware what they were testing and was responding to Silas Saying:

So, for any electronic device, there is a "breakeven point." No one knows exactly what this is!

[hoitoider]

I remember in the 70's-80's or so when some TV's had two off switches - there was a 'hard' off where it took a few seconds to get a picture again and a 'soft' off where the picture would come back on almost instantaneously. If the TV was in 'soft off' mode there would be a small red indicator light on, so of course it had to be plugged in. I think the hard off was called the 'power saver off' or something.

[Hero_Mike]

Originally Posted by hoitoider

I remember in the 70's-80's or so when some TV's had two off switches - there was a 'hard' off where it took a few seconds to get a picture again and a 'soft' off where the picture would come back on almost instantaneously. If the TV was in 'soft off' mode there would be a small red indicator light on, so of course it had to be plugged in. I think the hard off was called the 'power saver off' or something.

My parents bought a 28" colour console TV in 1980 - it had the normal "power" button, and could also be turned on via the remote. It also had a "master switch" which would turn off all power to the TV, including the small amount of power consumed by the remote sensor in "standby" mode. It also protected the TV against damage from overvoltage - I assume that it was an actual disconnect of the incoming power. The TV still took a few seconds to warm up. My relatively modern Sony CRT television still takes about 10 or 15 seconds to warm up and show a picture, though sound is heard instantly.

I inspected a firm that makes halogen lamps. There was a procedure called "burn-in" where the bulbs are left on for 48 hours at 100 degrees F. I've seen this with other electronic devices; no TV's though. I would suppose that TV manufacturers would have a similar procedures.

[Troberg]

I inspected a firm that makes halogen lamps. There was a procedure called "burn-in" where the bulbs are left on for 48 hours at 100 degrees F. I've seen this with other electronic devices; no TV's though. I would suppose that TV manufacturers would have a similar procedures.

That's common enough for some higher spec electronic components. The reason for this is the famous bathtub curve ( http://en.wikipedia.org/wiki/Bathtub_curve ). Basically, components fails early (due to manufacture defects) or late (due to age and wear), and in between there is a long reliable period. The burn in period is to weed out the bad ones.

[jason13]

Originally Posted by matches

Legends like this usually require some notion of a power surge when you first power up the item. It could have been true in the past, but modern televisions, just like modern computers and automobiles are simply better designed than that.

Any mechanical switch will produce small pulses of electricity, or "switch bounce", when thrown. One can design circuits and software to deal with the bounce (if the equipment is bounce sensitive), otherwise, your keyboard may produce aaaaaa instead of a or when you press CH+ on your TV remote, your channel might go 2-3-4-5-6-7-8 instead of 2-3.

I'm not sure what effect it has on the main power circuit, though, but I'm sure it's possible to account for it, although cheaper brands might leave those circuits out.

[Troberg]

I'm not sure what effect it has on the main power circuit, though, but I'm sure it's possible to account for it, although cheaper brands might leave those circuits out.

Switch bounce is about metal surfaces bouncing when they connect, causing digital equipment to count it as several operations.

This is not a problem with power circuits, although they have a somewhat similar problem from a different reason. When they are switched on or off, the coils in the transformer have inductance that can cause a power spike which can blast sensitive electronics. For this reason, they have filters that eats those surges. If you look into a power unit, the most noticable feature besides the transformer are the huge capacitors which are the important part of this filter. This filter also smoothes out the voltage and removes interference and voltage fluctuations.