VIZIO TV M550SV image ok, no sound

[alfredomfr1]

Perfect Image but no sound
I replaced this 2 capacitors (bulged) see the picture.
The speakers are ok.

Amplifier TPA3110D2
Pin 7: 18.24v
Pin 15,16,27,28: 18.31v

Amplifier LM4558
Pin 8 (VCC): 17.61v

I don't have a scope, my bad

[budm]

Re: VIZIO TV M550SV image ok, no sound

Do you get at the Headphone jack or at the RCA Audio line out jacks if the TV has those connectors?
Speakers are turned on in the on screen user menu sound setup?

[Electronic Handyman]

Re: VIZIO TV M550SV image ok, no sound

Hard to tell for sure from your pics if it's just dust but it does to me look like that board has moister damage.If water gets on a board it will cause white spots and corroded the circuit usually pins will rot on regulators etc too.

[TechGeek]

Re: VIZIO TV M550SV image ok, no sound

Are the speaker terminals loose? Check the connections.

[alfredomfr1]

Re: VIZIO TV M550SV image ok, no sound

budm: Headphone jack and RCA line out = No audio
EH: The board is in good physical condition.
Techgeek: Speaker terminal are ok

[budm]

Re: VIZIO TV M550SV image ok, no sound

budm: Headphone jack and RCA line out = No audio
EH: The board is in good physical condition.
Techgeek: Speaker terminal are ok

Then it is not headphone amp or the speaker amp problem then since line outs are way before the output section. May be the MUTE line is stuck on some how or the preamp sections are bad but since both channels are dead then it will have to be something in common such as power supply.

[alfredomfr1]

Re: VIZIO TV M550SV image ok, no sound

I can't found schematic for this board and there is not a replacement on ebay.
Can you drive me to fix this problem?

[budm]

Re: VIZIO TV M550SV image ok, no sound

If you have scope then it may be helpful to trace the audio from line out back to some kind of opamps which you should check the VCC (it may not use +/- supplies so the input will have to be bias at +input to get 1/2VCC at the output. You can also make audio probe by using powered PC speakers and a 1K and 1Uf cap in series to the input of the PC speaker, the end of the resistor can be used as a probe, the GND shield wire is connected to the chassis.

[dick_barton]

Re: VIZIO TV M550SV image ok, no sound

Here's the pdf for the audio amp.

Check Pin 2 (/Fault) and see if it is at 0V

https://cdn.badcaps-static.com/pdfs/...3ed5940034.pdf

[dick_barton]

Re: VIZIO TV M550SV image ok, no sound

Could you touch pin3 (or pin 12) of the TDA3110D2 carefully with a piece of wire or the leg of a resistor and see if you can hear any sound from the speakers.

[alfredomfr1]

Re: VIZIO TV M550SV image ok, no sound

I will look for a scope, I'll be back soon

[alfredomfr1]

Re: VIZIO TV M550SV image ok, no sound

smd fuses ok

[alfredomfr1]

Re: VIZIO TV M550SV image ok, no sound

I found a mainboard with a very good price, replaced and audio ok again.
Thanks guys for the help.

[tlsanjose1224]

Re: VIZIO TV M550SV image ok, no sound

Alfredo: can you let me know where I can find that mainboard?

[alfredomfr1]

Re: VIZIO TV M550SV image ok, no sound

friend sell to me his broken screen tv

[ljintexas]

Re: VIZIO TV M550SV image ok, no sound

I have now inherited one of these with the same audio issue..

[hardbox]

Re: VIZIO TV M550SV image ok, no sound

Could you touch pin3 (or pin 12) of the TDA3110D2 carefully with a piece of wire or the leg of a resistor and see if you can hear any sound from the speakers.

My TV speakers get sound when I do that..

[Sully805]

Re: VIZIO TV M550SV image ok, no sound

Its the electrolytic caps on the main board. Just keep replacing them until it works.
Or repair service

https://www.nickstvs.com/store/p1999/3655-0342-0150

[dick_barton]

Re: VIZIO TV M550SV image ok, no sound

My TV speakers get sound when I do that..

So as Budm has indicated the Audio amplifier is working. The other thing to check is that you have TV speakers set to on in the Menu.