[jj2005]

I've got a new sony KDLp3000 LCD and there's a humming noise that's audible with the sound off or even when the sound from the tv programme I'm watching is low. Is this normal? Should there be any humming noise at all?

[Shwing]

If it's a humming noise coming from the rear of the set, then yes, it's common for an LCD screen to emit this.
I believe it's to do with the backlight of the set - and can vary in loudness depending on your backlight setting (a bit like a dimmer switch makes a louder hum as the light is turned down).

Hope this helps.

[jj2005]

Further info: If I switch from AV to PC it completely disappears.

[jj2005]

I've tried it even with no connections into the TV and it's still the same.
I wonder if Sony owners could do me a favour and test theirs and let me know if it's the same. Just stand next to the tv and turn the tv on and mute the sound and tell me if you can hear a high pitched humming noise. Much appreciated. (If you do hear a noise is it any different if you change the input to PC instead of AV or TV?)

I have a KDL-15G2000 which has the same problem. It does emit a similar level of audible tone on each backlight setting other than 'Max' (in which the sound disappears). When the television's volume is muted or reduced to 'Min' the humming becomes far less audible (though other volume adjustments make no difference), so sound through an external AV amplifier/receiver seems to be a suitable solution. The problem appears to be a regular occurrence as, despite what I was led to believe by Sony support (who claimed the LCD should not be making any sort of buzzing noise at all), the replacement was exactly the same. Perhaps it's a feature of Sony's cheaper range.

Alternative thread: http://www.avforums.com/forums/showt...04#post6706704

[J450N]

My KDL40V3000 doesn't seem to hum at all... Mind you, my backlight is set quite low.

Just noticed this hum on my KDL 40V2500. Funny what you notice when you little ones get you up at 5:00 am. I have had this unit for 1.5 yrs but an not sure if this is a new noise or if I have only just noticed it.

[cjohnson6]

Originally Posted by jj2005

Further info: If I switch from AV to PC it completely disappears.

When set to AV it will probably be following the 50Hz frame rate (PAL) which is linked to the mains frequency... On a PC it will probably follow your PC frame rate which is 'proabably' 60Hz.

Usually it's cheap transformers in the unit that are resonating with the line frequency..

TVs are like that, built cheap....

[Lt. Dang]

I have Sony 40V3000 which does not hum at all - either on AV or PC input.

Just tried a few different backlight settings too and still no hum at all.

Hope this helps.

Regards,

Lt. Dang

mine hums too

Hi, I am new to the AVForum and thought I might share my current experiance with the problem of noisy humming lcd tv's.

I just bought a Sony KDL32W5500U from Dixons Online, good price £649 delivered, its a great TV with good picture and features, but the backlighting inverter 'hummed' so much I had it exchanged (with no fuss to Dixons credit) as I assumed it must be a fault. But the new replacement just delivered is exaclty the same, so I am now resigned to the fact that this is a characteristic of this Sony lcd TV. How can anyone be expected to put up with intrusive humming during thoes quiter TV moments ? I am now going to reject this TV and get my money back and continue the search until I find a 32" LCDtv that doesn't hum, assuming one exisits.

I'll post my result if I get one !

i exchanged mine,new one doesnt hum

[krzysbw]

I bought 32w5500 from Dixons online, had it exchanged twice already and each of them made humming noise. It could be just Dixons stock as none else seems to be complaining about it or people just don’t notice the noise. I really like this TV but I am looking for a different make now. I am tempted to get new Samsung but its “operational noise” has been mentioned in some reviews. It seems to be impossible to get a quiet set.

If the hum only occurs on the AV input it could be a poorly shielded cable connected to the input that is picking up mains hum or similar.

Try removing or moving the cable from the AV input to get an initial test.

If this works try a better (doesn't have to be expensive) SCART cable. Generally fatter is better as they are more likely to have proper shielding.

Hi me back again. Its not just Dixons stock that hums. After sending two kdl32w5500u sets back to Dixons Online, the one from the flipping Sony Centre hummed even worse and I had paid another £150 for the privalage. Its exactly the same problem each time with this model i.e humming relating to the backlighting settings. Trust me its not the cables or input selections that are making this noise. I hope Sony recongnise the problem soon, as the TV is great in all other respects, just one bad component fitted badly. Next stop, the Samsung equivalent.

[ukmikk]

My Samsung doesn't hum. At all.

[javadevinfo]

Hi, I just bought a Sony KDL 37w5500(my first LCD TV) and am very disappointed with this buzzing noise. I set the backlight value to max(after searching the web) which has helped to an extent - with a bright scene it is off but if the scene goes dark it comes on. So I am not sure if I prefer it on all the time or switching on and off as the brightness level in a scene changes! Also when you change channel and the screen goes black for a second it comes on - a minor issue. Although I dont think I should have to listen to this buzzing at all. Its back to the shop tomorrow.

[cheddington]

Looks like i'm not alone in this, i'm currently trying to decide whether to keep my 40v5500 due to this noise. I've had a look on a few of my relatives tvs to try and investigate why I hear nothing on theirs. It seems that any humming is coming from lower down so is being masked by the tv also I noticed no open grill on where the humming is. On my Sony it eminates from near the top and through an open grill, I was also thinking it could be because the case is thinner?

For me the buzzing/humming goes when the screen is all white and loudest when all black, backlight helps little.

[javadevinfo]

The crux of this issue seems to be that as soon as an attempt is made to dim the backlights, the humming noise starts.
This is probably due to a step down transformer used to reduce the voltage going to the backlights.
This is a common issue with step down transformers, although a well made transformer should not hum significantly.

So there are two ways to tackle this issue:

- Replace the set until you get one with a step down transformer with a noise level that you are happy with.

- Minimise the situations where the set attempts to dim the backlights.
To do this I have used the following settings to stop the dimming in all but one situation.

(1) Picture->Backlight : this is an obvious one - set this to MAX.

(2) Picture->Advanced Settings->Adv. Contrast Enhancer : set to OFF
Note: This function appears to try to make blacks more black by dimming the backlights.

(3) ECO->Power Saving : set to OFF

(4) ECO->Light Sensor : set to OFF
Note : I though I had it sorted using the first 3 but the hum noise came back on in the evening due to this last setting.
It seems that when the ambient light level drops, this light sensor function will use the dimmer to turn down the backlights.

The only situation when the dimmer is still used is when you switch channels, for a second(or two) the screen goes black and the dimmer kicks in again. For me, this is a minor issue.

I suspect this hum is not evident in other models/brands as they dont use this dimming technique and keep the backlights on full at all times.

I hope this info helps.

[cheddington]

Tried all the settings above but none made much/any difference, even the backlight setting made no noticeable difference.

I messed around with all of the settings today and the only thing that made any difference was when I changed the input to PC, infact it reduced the noise quite a bit. Any idea why this is?

Thanks for the informative post btw.

[javadevinfo]

Hi cheddington,
You may have a different problem to mine. However I did notice that each input source has its own settings. I stopped the noise on the TV input using the above settings but when I switched to AV2 for my DVR the noise came back - I had to set the setting(above) again for the AV2 input source. You could compare the setting on PC with those on TV to see what the difference is.

[newbie1]

No humming at all from our Panasonic and Samsung LCDs. The Loewe was also hum free until the power supply failed and was replaced, which then somehow made an internal fan start to hum. Now fixed under warranty.

v. annoying once you notice that hum, and most shops are so noisy you have no chance to hear it before you buy.

[cheddington]

Originally Posted by javadevinfo

Hi cheddington,
You may have a different problem to mine. However I did notice that each input source has its own settings. I stopped the noise on the TV input using the above settings but when I switched to AV2 for my DVR the noise came back - I had to set the setting(above) again for the AV2 input source. You could compare the setting on PC with those on TV to see what the difference is.

I've tried every setting on every scene mode on several of the inputs and nothing made the noise any better, the only time it gets better(prob about 50%) is on PC mode which I find a bit random. Thinking I might have to bite the bullet now and get in touch with the retailer before its too late.

I feel i'm being a bit picky but after paying £718 I wasn't expecting this, worse thing is im happy with most aspects of the TV and have no backlight bleed, stuck or dead pixels. Its not that its really loud but its the high pitched nature of it thats annoying, sigh will I ever find the perfect TV for me.

Originally Posted by newbie1

No humming at all from our Panasonic and Samsung LCDs. The Loewe was also hum free until the power supply failed and was replaced, which then somehow made an internal fan start to hum. Now fixed under warranty.

v. annoying once you notice that hum, and most shops are so noisy you have no chance to hear it before you buy.

Hi newbie1, did you test the Sony TVs for the humming? I dont like the panel lottery of Samsung TVs but may consider Panasonic if this becomes a problem. Talked to other owners on here though and they say theirs is fine, whether or not they sit v.far away watching action films in 5.1 surround is the difference I dont know.

[cheddington]

Can anybody who has replaced their V or W series SB TVs because of this issue please comment if the replacement fared any better.

[Lt. Dang]

Originally Posted by cheddington

Can anybody who has replaced their V or W series SB TVs because of this issue please comment if the replacement fared any better.

Well Sony can make quiet TVs. My 40V3000 is silent. No humming, even up close, whatever the backlight settings etc.

Basically, if I had a TV where the humming spoilt my viewing pleasure I would take it back.

Regards,

Lt. Dang

[cheddington]

Got a replacement 40V5500 and this has the same thing which leads me to believe it is classed on normal on this set or early batches have this problem (man date of 03/09). On top of this the clouding on the new one is worse than the previous one I had. Not really sure where to go now, thinking about trying the W equivalent while the 3 year warranty is still active but also thinking about other brands now.

[javadevinfo]

Hi,
This humming problem also exists on the Sony KDL 37w5500(See my previous posts).

The new LED TVs have no CFL backlights and therefore should not suffer from this humming issue. On the other hand they are about 33% more expensive and they may suffer from their own "bleeding edge technology" issues!

Its a difficult issue - trying to find a quite piece of equipment in a noisy shop environment. I had to go back 3 times with a new laptop because when I got them home to my nice quite room, the cooling fans were unbearably noisy and distracting. I finally persuaded the shop(Dixons) to let me use one of their quite offices to try before buying.

I have the Sony KDL S3000, I noticed the humming just the other week, which is coming from the back of the tv and is louder near the left side panel, not sure if it just started or was there when i bought it. It seems to be the backlight. If the back light is set to either 1, 6 or 7 the humming stops, any other setting produces the humming.

My computer is connected by HDMI, there is no humming what so ever from this channel what ever settings i use.

Why the humming stops when the back light is set to 1, 6 or 7 i have no idea but as other people have mentioned it sounds like the back light controller or transformer, i will be looking for a replacement as it's beginning to bug me to much now that i have noticed it, any recommendations, thanks.

[OllyMason]

Originally Posted by javadevinfo

Hi,
The new LED TVs have no CFL backlights and therefore should not suffer from this humming issue. On the other hand they are about 33% more expensive and they may suffer from their own "bleeding edge technology" issues!

Hi all, I've noticed this too on some LCDs but if looking for a new one, a shop's rarely a good place to test. Can anyone confirm/contradict whether this is a backlight issue, and therefore absent on LED backlit TVs for sure?