# LCD TV Audio Problem



## suptob (Jul 8, 2010)

Hi, I was surfing the net looking for a solution to my problem, and I came across this Forum, so here is my question:

I've got a 26" LCD TV about 2 years old (Global Tech_HD brand), working perfectly until last week. Whilst watching a movie, the audio disappeared and was replaced by a regular clicking sound. I turned the set off, and after a couple of minutes, turned it on again....worked ok for another 15/20 minutes and then the same problem appeared. Turned the set on and off a number of times but all I get now is the clicking sound... picture is perfect though.
I hoped it may be a simple problem, but when I removed the back, I could not identify the audio amp/IC

AV inputs and outputs do not work.

There's no visible problems on the main board and all electrolytics look ok, but most components are surface mounted and I can't seem to locate the audio section.
Can anyone shed any light as to what component marking I should be looking for, or any other suggestions/ideas?

Thanks in advance.


----------



## Done_Fishin (Oct 10, 2006)

had a quick look around the net but came up with no info on the details you gave above.

A lot of boards used in TV's are microprocessor based these days so it could be a firmware malfunction, an audio failure or even a component feeding the audio circuitry. 

I would suggest that you try several different input output methods to see if you can isolate the point of failure. Try playing a CD or DVD using the SCART or equivalent input., some music via external inputs also try playing the sound from your set through to another audio amplifier using whatever options are built into the TV .. if some appear to be working normally then you will be able to deduce what circuitry is affected.


----------



## suptob (Jul 8, 2010)

Thanks, I tried all the inputs and outputs and none of them work, so that's why I though it may have been a failed amp chip, don't know about firmware as I haven't been able to locate this brand on the net...I think it's a generic model badged for different suppliers, the main board suggests it is made in Korea.


----------



## Done_Fishin (Oct 10, 2006)

only thing you can do is follow the wiring back to the board and then look for a couple of large capacitors and a nearby audio chip. Check the Chip ID and search on the net for a datasheet which should give you some idea of the workings. Check for correct voltages around the chip and hope that there is no mute mode (from the datasheet). Check to see if you get sound when trying to inject an audio signal into the input. Do that using a capacitor and possibly a resistor.


----------



## suptob (Jul 8, 2010)

The audio chip is a Texas Instruments TPA3123D2, too small and fiddly for me and my eyesight! Might have to see if I can get it repaired cheaply, otherwise I'll see if I can just use it as a monitor.


----------



## Done_Fishin (Oct 10, 2006)

It's Surface mount, requires a hot air pencil or soldering station to remove & replace. Inexperienced techs may end up tearing tracks whilst trying to remove it. 

pdf datasheet is *here* . 

I note that there is a mute pin .. might be in mute mode.


----------



## suptob (Jul 8, 2010)

Thanks, I noticed the mute function, but not the problem. I won't even try to replace the chip, don't have the necessary equipment or expertise. I'll see if I can find a local repairer who is willing to tackle it at a reasonable cost.
Cheers.


----------



## Sophia.dicosta (Jul 8, 2010)

If your LCD TV is producing continuous clicking sound then it may be the problem of bad capacitor used in power supply or if this sound is not continuous then it may be caused by the monitor relay opening and closing and this sound is considered as normal in that condition.


----------



## suptob (Jul 8, 2010)

Sophia.dicosta said:


> If your LCD TV is producing continuous clicking sound then it may be the problem of bad capacitor used in power supply or if this sound is not continuous then it may be caused by the monitor relay opening and closing and this sound is considered as normal in that condition.


Thanks I thought about bad capacitors producing this problem, I don't think they would be in the power supply though, as it's only the audio which is affected, the video is ok. Either way, I don't have the tools to work on this board with surface mounted components.

Still trying to find some local repair shop which can try to attempt the repair at an affordable cost.


----------

