TV LG 55GA6400 No sound through the internal speakers

[alfredomfr1]

Problem: has no sound through the internal speakers.
Sound OK through headphones.

Main Board: EBR76466206
Speakers Connector Voltage: L+, L-, R+, R- to Gnd: 12.37v
Speakers Resistance: 8ohm

[Diah]

Re: TV LG 55GA6400 No sound through the internal speakers

check the menu setting of sound out put. be sure its listed out speaker

[R_J]

Re: TV LG 55GA6400 No sound through the internal speakers

The board uses a seperate amp ic for headphones, and main speakers, Like above post... check the menu settings to see if the speakers are turned off

[alfredomfr1]

Re: TV LG 55GA6400 No sound through the internal speakers

Internal Speakers are ON in the menu setting

[R_J]

Re: TV LG 55GA6400 No sound through the internal speakers

Download the service manual, there is a schematic of the main board.
12v on each speaker wire to ground is normal (half of the 24v vcc to the ic)
My guess is the audio output ic is ok, if an output was bad, usually you will have 0 or 24 volts on the speaker lines
I suspect either the headphone jack (sending a mute signal to the speaker amp ic) or maybe something in the firmware is corrupt?

[alfredomfr1]

Re: TV LG 55GA6400 No sound through the internal speakers

I cant found the schematic, do you have a link?

[alfredomfr1]

Re: TV LG 55GA6400 No sound through the internal speakers

I replaced the speakers and same thing, no sound

[petehall347]

Re: TV LG 55GA6400 No sound through the internal speakers

check internal speakers for short then check audio ic working voltages .

[R_J]

Re: TV LG 55GA6400 No sound through the internal speakers

I cant found the schematic, do you have a link?

Check post #5

[alfredomfr1]

Re: TV LG 55GA6400 No sound through the internal speakers

Thanks for your help R_J, I will check the schematic and let you know tomorrow

[Diah]

Re: TV LG 55GA6400 No sound through the internal speakers

Internal Speakers are ON in the menu setting

in this case you need to try send to the set IN_STOP command to rolling back all driver and firmware as factory condition. you can find here in this forum how to

[Trevtron]

Re: TV LG 55GA6400 No sound through the internal speakers

I had a similar fault recently with a Samsung set, it was the headphones jack. The set thought the headphones were plugged in so it blocked the signal to the speakers.
Headphones were not a requirement for the owner so I just bypassed the contacts and sound was restored.

[nomoresonys]

Re: TV LG 55GA6400 No sound through the internal speakers

Did you try a factory reset? might need a firmware update/reapply.

[nomoresonys]

Re: TV LG 55GA6400 No sound through the internal speakers

You probably already tried unplug tv from outlet for a minute.

[nomoresonys]

Re: TV LG 55GA6400 No sound through the internal speakers

Try holding power button pressed on tv for 10 to 15 seconds and or holding both power button on tv and remote for 10 to 15 seconds.

[petehall347]

Re: TV LG 55GA6400 No sound through the internal speakers

[QUOTE=alfredomfr1;891561]Problem: has no sound through the internal speakers.
Sound OK through headphones.


Speakers Connector Voltage: L+, L-, R+, R- to Gnd: 12.37v


check voltage across the speakers

[nomoresonys]

Re: TV LG 55GA6400 No sound through the internal speakers

Hook up an external device to the “TV audio out” input. This will be the test to see if it is a TV circuit board malfunction or the speakers are faulty in your TV.

[nomoresonys]

Re: TV LG 55GA6400 No sound through the internal speakers

Try pressing mute button 3 times.