Hi frequency noise from TV...

Ronan H

Hi...

For the last couple of days my wife, myself and some other people have noticed a really subtle but audible high pitched noise coming from the TV (im assuming its the TV). The strange thing about this is that its even audible when the TV is switched off at the mains?!

In case its pertinant, this was happening on a PC at work and when i adjusted the refresh rate of the monitor it stopped immediately, the only reason i mention that is that the sound was exactly the same, only louder. There arent any settings on the TV for adjusting the refresh rate or anything like that, just the standard settings.

I might add that some people cant hear it for some reason, and NO we wre not hearing things and we are not CrAzY :eek:.

Its definitely there, no doubt. My suspicion is that the TV is goosed, although it still works, but maybe its struggling... Theres also a SKY box, DVD player and video player on the same unit, but i still suspect its the TV.

Has anyone had any experience of this or does anyone know what it is? Its really frustrating and makes it difficult to spend a long period of time in the room as its a really shrill noise, really penetrating...

Any help would be greatly appreciated...

Crazy Head

zilog_jones

CRT TVs and monitors always make a high pitched noise. They tend to get worse over age - I forget what actually causes the noise. One of our TVs is about 9 years old now, and the noise starts to get louder after the set is on for a few hours.

Head wrote:

The strange thing about this is that its even audible when the TV is switched off at the mains?!

Now that doesn't sound right. The noise I explained above only happens when the CRT is on. You sure it's not something else? Modern transformers (ones that don't have big heavy coils in them) can also make similar noises. Our DVD player makes some gammy noise when on standby. Try unplugging everything in the room.

I might add that some people cant hear it for some reason, and NO we wre not hearing things and we are not CrAzY :eek:.

The noise is at a pretty high frequency, bordering on ultra-sonic. It may be 15.625kHz, i.e. the horizontal scan frequency of a TV - again I forget. Many people will not be able to hear sound of that high a frequency, especially if over about 25-30 years old.

Ronan H

zilog_jones wrote:

Now that doesn't sound right. The noise I explained above only happens when the CRT is on. You sure it's not something else? Modern transformers (ones that don't have big heavy coils in them) can also make similar noises. Our DVD player makes some gammy noise when on standby. Try unplugging everything in the room.

Everything is plugged out, very strange that its still audible though... Maybe someone did a sneaky install of one of them ultrasonic yokes they have outside shops to send loiterers on their way :rolleyes:.

In all seriousness though, i think its ample grounds for a 42" plasma...ahem...

Hint Head

CreepingDeath

Head wrote:

Any help would be greatly appreciated...

Crazy Head

Some light dimmer switches make a high pitched noise.
Do you have a surround sound system ?
It could be coming from those speakers instead of the TV.
A nearby power cable might be inducing a small current in the speaker cables, causing the high pitched sound. Do you have a tangled mess of wires at the back of your TV ?

Phone chargers and laptop power supplies are culprits for high pitched noise too.

Ulsterman 1690

The strange thing about this is that its even audible when the TV is switched off at the mains?!

Dodgy coil or transformer in the (switch mode) power supply circuit

There arent any settings on the TV for adjusting the refresh rate or anything like that, just the standard settings.

There wont be (unless its multistandard and even then the switching would be automatic)

slicedpanman

Head wrote:

In all seriousness though, i think its ample grounds for a 42" plasma...ahem...

Hint Head

Get an LCD rather than plasma... it will have a (much) lower power consumption (about 10 times less)... better for your ESB bill and the environment

watty

slicedpanman wrote:

Get an LCD rather than plasma... it will have a (much) lower power consumption (about 10 times less)... better for your ESB bill and the environment

but LCD & Plasma a poorer picture than CRT. You need to spend close to €1800 to get a decent LCD or Plasma.

There is not a 10x difference between Plasma and LCD. For same size it is more like X1.5 to X 2, due to LCD backlight.

If you hear the sound when TV is switch off at mains then it is a Power supply in the Sat, DVD or Video player boxes.

You can't change the refresh of TVs. It has to match the transmitted picture of 25i. On LCD/Plasma, sometimes the native refresh is USA 30Hz or 60Hz, so picture is blurred by frame rate conversion, especially on movememt.

slicedpanman

watty wrote:

There is not a 10x difference between Plasma and LCD. For same size it is more like X1.5 to X 2, due to LCD backlight.

I've been mis-informed... thanks for the correction Watty :cool:

My current CRT is almost at the end of its life and was thinking of getting a new LCD based on my (mis-)information. Whats the definitive thing to check to compare power comsumption on various models? Is it the Watts listed by the supplier?

Apologies for the OP for going off-topic

Ronan H

No sweat breadman!

Just to clarify, i hear the noise when everything is plugged out, SKY, DVD, Video etc... Absolutely nowt plugged in.

Ro

byte

When does the noise stop? If it was a faulty capacitor or something, the noise could remain until it drains. You might hear the noise "wind down".

steveon

Ulsterman 1690 wrote:

Dodgy coil or transformer in the (switch mode) power supply circuit

I would concur that the likely cause is air circulating around a coil inside the tv, which causes a very high pitched ringing sound, can be extremely annoying and common in some sets.The solution is to find the coil ringing by opening the set (Not always easy to locate)
and tapping with an insulated screwdriver and then covering it with a heat proof glue. I would not recommend it unless you know what you are doing, or alternatively to replace the coil itself

Ronan H

It never stops, and it seems worse when the TV is plugged out! Crazy or what...

Ta for the suggestion steveon, i know a guy who is handy with circuit boards and might have a look for me...

I think its time for a new TV... Ill get the old one fixed and put it on Jumbletown!

Head

Booms

Just a few days ago, one of the guys I work with was complaining of a high pitched whine, which occasionally stopped for a second, then came back. I couldn't hear it, being hard of hearing, and he decided it must be the printer/fax further down the room.

Turned out it was my hearing aid whistling in my shirt pocket.:o


Two thoughts:

Take all your equipment out of the room, one piece at a time, until it stops?

If you put your hands over your ears, and the sound continues, it might be worth getting a check up, could be something like tinnitus.

Bet a 42" plasma would cure it, though!

Ronan H

Booms wrote:

Bet a 42" plasma would cure it, though!

Hah it would indeed...

I hadnt thought about removing items from the room to isolate what one is causing the racket. Im nearly 100% sure that its the TV but ill try the process of elimination just to be fully sure. Great suggestion, thanks!

Tinnitus Head

Ronan H

Aha! After moving around the TV and other bits, the noise was still there, just that bit too subtle to pinpoint where it was coming from, so i gave up...

Then just a few minutes ago my wife calls me in and the noise has turned into a horrible screech, which was coming from the opposite corner from the TV, where there was a lamp and a remote control... ... ... ... ... Lamp on, lamp off, bulb out, bulb in, plug out, plug in...i still can hear it... Feckin remote control wailing away beside the lamp :rolleyes:. Batteries are flat or either dying a death, so i take it out and change the batteries and all is well in the Halpenny household, no Tinnitus and no 42" plasma...

Im still curious about why this happens though, anyone shed some light on it? In case its pertinent, one of the spiral connectors for the batteries had some of the green crusty stuff on it (its an OLD remote), as if a battery had leaked or something... Other than that its fine, but im still wondering why it happens...

Head

byte

Green crusty stuff means the battery is leaking, and should be thrown out, not charged! Since remote controls have such a low drain, I personally wouldn't use rechargeable batteries, due to the very long times between charges.

cast_iron

He did say change, not charge.

byte

cast_iron wrote:

He did say change, not charge.

LOL I'm blind! Sorry about that.

Charles Slane

I had a problem with a high-pitched whine coming from my TV earlier tonight - it turned out to be James Blunt at the Live Earth concert

5h4mr0(k

Good to see it resolved - before you put your boot through the TV.

So much remotes making your life easier!

Ronan H

Charles Slane wrote:

I had a problem with a high-pitched whine coming from my TV earlier tonight - it turned out to be James Blunt at the Live Earth concert

:D:D Very nice!

Stitches Head

gerryo

Head wrote:

Feckin remote control wailing away beside the lamp :rolleyes:. Batteries are flat or either dying a death, so i take it out and change the batteries and all is well in the Halpenny household, no Tinnitus and no 42" plasma...

Might have been gas escaping from the battery.
There's a small safety vent in batteries to let gasses escape safely, might explode otherwise.

A dead or dying battery can leak & a chemical reaction generates gasses, these escape out the vent. Have heard this before, it's usually very low volume ticking noise, then again, may not sound the same for all batteries.

Booms

So when are you getting the 42" remote?

Ronan H

Hah, Boom Boom, as Basil Brush would say! Nice one...

Ta for the battery info Gerry...

Ronan Head