I have a two year old Panny 42px50U set and recently it has been making this weird clicking/buzzing sound from the TV speakers. It's hard to describe, but similar to what you would hear if you were hooking a speaker up to your receiver while the receiver is on (eg- you get this quick scratchy noise until you get the leads from the speaker wire seated). The noise happens on either SD or HD channels. Any thoughts on what this might be?

If you're sure it's coming from the speakers, check first with different inputs selected to make sure it isn't coming from a bad input source or cable connection (the most likely problem).

Next possibility to consider is that the set is picking up ground loop hum caused by having multiple pieces of equipment plugged into different wall sockets with signal ground lines connected in common to the TV. To identify the source, try unplugging cables one at a time, then all of them except the TV power if that doesn't work.

If you're not sure that the sound is coming from the speakers, consider that you may have a case of transformer hum, which is a common fault with plasma sets. The key symptom is that it gets louder when the screen content is bright white, and quieter when the screen is dark.

If none of the above helps, you might be developing a bad amp on the audio board, which would need confirmation by Panasonic for replacement.

If you're sure it's coming from the speakers, check first with different inputs selected to make sure it isn't coming from a bad input source or cable connection (the most likely problem).

Next possibility to consider is that the set is picking up ground loop hum caused by having multiple pieces of equipment plugged into different wall sockets with signal ground lines connected in common to the TV. To identify the source, try unplugging cables one at a time, then all of them except the TV power if that doesn't work.

If you're not sure that the sound is coming from the speakers, consider that you may have a case of transformer hum, which is a common fault with plasma sets. The key symptom is that it gets louder when the screen content is bright white, and quieter when the screen is dark.

If none of the above helps, you might be developing a bad amp on the audio board, which would need confirmation by Panasonic for replacement.

Thanks, will check these things tonite.

Well I unplugged everything except the TV and cable box and the noise is still there. When I turn off the cable box, the noise is gone, but I figure that makes sense. It's very annoying. I asked my wife what she thought it sounded like and she said it was more of a popping sound. It does it in short bursts. It's not overly loud, but very noticeable. I usually use the TV's speakers when watching SD TV and only my Rx for everything else (HD, movies), but looks like I'll have to either get this fixed (dollar signs are already flashing through my head) or just use my Rx all the time.

bump. any other thoughts on this? I checked all connections as well and nothing is loose. And to add another description of the sound it sounds like short "zapping" sounds.

bump. any other thoughts on this? I checked all connections as well and nothing is loose. And to add another description of the sound it sounds like short "zapping" sounds.

If you're talking about the Jedi Lightsabre type of zapping sounds, then that's likely the cable box. I developed that issue on my Motorola 6412 after I had it a few months (albeit it was a rental from the cable company.) It was loud, infrequent, and lasted only a couple seconds. I haven't heard it since switching to satellite and getting a new receiver, so I have no doubts it was the cable box or their signal.

If you're talking about the Jedi Lightsabre type of zapping sounds, then that's likely the cable box. I developed that issue on my Motorola 6412 after I had it a few months (albeit it was a rental from the cable company.) It was loud, infrequent, and lasted only a couple seconds. I haven't heard it since switching to satellite and getting a new receiver, so I have no doubts it was the cable box or their signal.
great analogy. the jedi sound is exactly what is sounds like. should I swap out the cable box? the noise stopped for a bit this morning. it seems quite random, although it was doing it all last night.

It wouldn't be hard to test their signal if you're getting it that often. Try a direct cable line to the TV, if you still hear it, then it could be electrical issues in their cable line and not just the receiver.

I'm betting on the receiver though, after my experiences.

If you don't hear it with the cable box disconnected from the TV, it the problem is either the cable box or it's some pretty bad noise coming in on the cable ground - but in any case, not a problem with the TV.

If you're talking about the Jedi Lightsabre type of zapping sounds, then that's likely the cable box. I developed that issue on my Motorola 6412 after I had it a few months (albeit it was a rental from the cable company.) It was loud, infrequent, and lasted only a couple seconds. I haven't heard it since switching to satellite and getting a new receiver, so I have no doubts it was the cable box or their signal.

I agree that it's the cable box. Occasionally with my Scientific Atlanta box, I might switch to a higher channel number [over ch. 290 for example] and immediately notice the added "popping audio crackles" [channel's content audio is fine]. The only way to get it back to "normal" is turn the box off, and then back on to a lower number channel, and try again the higher channel (as it doesn't do it every time). Probably will take it in for a swap eventually, but it's not a regular problem, just occasionally.

thanks all. I came home tonite and didn't hear any popping, but next time I do, I will directly plug the cable line into the TV, bypassing the STB. If the noise stops, I'll know for sure.

well, the sound is back. Sounds like Darth Vadar is in the room. I disconnected the catv cable from the STB and went direct from the wall to the TV and sound was gone. So does this mean the STB is bad?