Buzzing TV - stops buzzing when tilted back

Reply

  #1  
Old 06-22-13, 01:20 AM
Member
Thread Starter
Join Date: Jun 2013
Posts: 3
Received 0 Votes on 0 Posts
Buzzing TV - stops buzzing when tilted back

Hi, I have a Techwood LCD TV that when running buzzes, however, when I tilt the TV back the buzzing is reduced the further back it's tilted.

I read a while ago somewhere that this might be caused by a wire from the sound getting too close to a power board (I don't really know much about electronics).

I have taken the back off the TV before to change a faulty board so am prepared to do that with your guidance, assuming it's something simple like moving the sound wires. I can provide photos of the TV's innards if needed, but first I just want to see if anybody knows what the problem could be.

Thanks.
 
Sponsored Links
  #2  
Old 06-22-13, 02:52 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 53,083
Received 372 Votes on 349 Posts
Welcome to the forums.

I've never worked on any Techwood electronic equipment. You had the back off to work on it....did you move or disturb any of the wires. Most wiring that would cause a hum is usually shielded. You're just going to have to play around with it.
 
  #3  
Old 06-22-13, 03:19 AM
Member
Thread Starter
Join Date: Jun 2013
Posts: 3
Received 0 Votes on 0 Posts
No the buzzing has been there long before I opened it up, though it seems to be getting very slowly worse.
 
  #4  
Old 06-22-13, 03:59 AM
Member
Join Date: Jan 2011
Location: United States
Posts: 2,446
Received 0 Votes on 0 Posts
Just a guess on my part as I know more about computers than I do television sets. I am thinking though that maybe there is a separate sound board that needs to be replaced. If you have the model number I can try to look up technical specifications and see if they say anything about a separate sound board. Be prepared though to pay a good bit for a new board. Of course this is a different thing but I have a Panasonic DVD recorder that I was going to buy a board for and the price was quite high. I don't know now what the price was just that it was more than I was willing to pay.
 
  #5  
Old 06-22-13, 06:48 AM
Member
Join Date: Apr 2007
Location: Near Buffalo, NY
Posts: 4,239
Received 0 Votes on 0 Posts
Is there something in the vicinity that is always on when you're watching TV? Fluorescent light? Neon clock? Computer?

Lava lamp?

Seriously, other electrical and electronic devices can produce interference. Shut off everything else and see if the cause is external to the TV.
 
  #6  
Old 06-22-13, 07:38 AM
Member
Thread Starter
Join Date: Jun 2013
Posts: 3
Received 0 Votes on 0 Posts
Hmm okay so I just took the back off to get some photos of its insides, the buzzing is definitely coming from each speaker.

http://i.imgur.com/uoa8i1x.jpg
http://i.imgur.com/gr0K2kL.jpg
http://i.imgur.com/4mmgkjW.jpg

I turned it on a few times and angled it in various positions but the volume of the buzzing stayed the same. But then when I put the back on and put the TV back into its stand I turned it on, tilted it back again and now the buzzing is barely audible.

The only difference is that I only put four of the screws in and didn't screw them very tight so maybe previously the back was pressing on something. It seems like angling the TV when it's in its stand also could perhaps be changing this pressure until I get it in the 'sweet spot'.
 
  #7  
Old 06-22-13, 05:06 PM
Member
Join Date: Jan 2011
Location: United States
Posts: 2,446
Received 0 Votes on 0 Posts
It looks to me that the problem is not so much in the speakers as they look fine but probably on the board in the middle. Not knowing the exact model though I am only guessing at it. Could be too there is something on the back of the case that is shorting out the sound area of the main board and when you move the television the problem then goes away.

Or it could be a board that has warped over time because of just being on for hours on end day after day. Computer boards can get warped too because of heat build up and malfunction but they are not as likely too because of their fans. With a television though there is very little that will keep it cool except the vent holes.
 
  #8  
Old 06-23-13, 01:55 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 53,083
Received 372 Votes on 349 Posts
boxy......what you are describing is the cabinet resonating. Very common problem due to the use of high quality plastics.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description: