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-   -   42 lg3000 (http://www.badcaps.net/forum/showthread.php?t=33934)

sean-tek 12-23-2013 12:47 AM

42 lg3000
 
Hi All,

Iv just been given the above TV from my dad as its making a really annoying whining noise so he went and bought a new one. He said to me that the whining noise used to stop after around 15 minutes or so of being on. Now however it doesn't stop at all, I can vary the pitch of the whining by changing the setting of the backlight up or down. Or putting the TV into different picture modes ie sport, cinema etc.

Now my suspicion is its the inverter board(s) having taken the back off and had a look the boards are as below. Now with the exception of this annoying noise the TV is working absolutely fine. Anyone else agree with my diagnosis or have any other ideas on what could cause the noise?

Vit71053.50 logah rev 3
Vit71053.51 logah rev 3

newtothis 12-23-2013 12:11 PM

Re: 42 lg3000
 
Sounds like interferance from the invertor cable... I have it on a set here.... though yet to figure how the hell to stop it. If I move the inverter cables away from the speaker cables it quietens... Does yours do the same?

sean-tek 12-23-2013 12:14 PM

Re: 42 lg3000
 
Hmm Il check when I next take the back off. Dad said it never used to do it and when it first started it would go after around 10 minutes. Unfortunately now it doesn't go. I found a pair of the inverters on ebay for 29 with a warranty so iv bought them. Will try fitting them when they arrive and let you know if that cures it

seanc 12-23-2013 06:46 PM

Re: 42 lg3000
 
My parents 42LH3000 does this when displaying blue or black - e.g Sky HD EPG or blue screen as you change channel. Bugs me but they don't notice.

sean-tek 12-28-2013 08:51 AM

Re: 42 lg3000
 
So after replacing the inverters its still doing it, however it stops after about 2 minutes of use, then it wont return until I turn the tv off and leave it 5 minutes, then another 2 minutes of this noise followed by silence. Iv just ordered a new PSU board to see if that will solve it failing that il just put up with it

T-con 12-29-2013 06:48 AM

Re: 42 lg3000
 
Maybe a psu problem, sometimes the trafo makes hi freq. noise when capacitors are leaky.

sean-tek 12-31-2013 12:40 PM

Re: 42 lg3000
 
Unfortunately not a psu issue either although on the plus side I now have a spare set of inverters and a spare psu board. Although absolutely no idea whats making this noise :(

tom66 12-31-2013 01:02 PM

Re: 42 lg3000
 
Try using a cardboard tube to isolate source of sound?
Tried unplugging speakers to see if it goes away?

sean-tek 12-31-2013 01:21 PM

Re: 42 lg3000
 
Sound is still there with speakers unplugged, il go round it with a cardboard tube tomorrow although due to the frequency of the noise it kind of sounds like its coming from everywhere :-( it definitely changes frequency when I adjust the backlight settings like set it to movie, sport etc. The best way I can describe it is similar to the sound of the flash charging on an old disposable camera but louder.


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