Panasonic TC-42PX14 no sound internal speakers

[jaimegmr]

I have a Panasonic TC-42PX14 (service manual here) that has has no issues other than having no sound through the internal speakers. The Red LED stays on and does not indicate a failure. I went into the self-test diagnostic screen and everything was OK. I tried the TV and see the black and white fuzzy image but hear no white noise. I connected an HDMI video player and also got no sound through the internal speakers.

SPDIF audio output works through.

I checked the audio menu settings and the internal speakers are ON according to the menu.

I checked the connector that goes from the power supply to the "A" board and it has 15V.

My next troubleshooting idea was to connect a logic analyzer to the I2C audio data lines going to the TI TAS5709 amplifier chip. Or I might just replace the amplifier and see if that fixes it. Any other ideas?

[tw2005]

Re: Panasonic TC-42PX14 no sound internal speakers

I have the Australian equivalent and the TV auto mutes on analogue TV, no signal, white snowy picture. Was the HDMI player configured to output sound via HDMI?

When watching TV normally are you saying no sound also?

[jaimegmr]

Re: Panasonic TC-42PX14 no sound internal speakers

I have the Australian equivalent and the TV auto mutes on analogue TV, no signal, white snowy picture. Was the HDMI player configured to output sound via HDMI?

When watching TV normally are you saying no sound also?

The HDMI player automatically outputs audio on the HDMI. The audio data gets to TV, since I can hear it out of the Optical SPDIF connector, but it doesnt come out the internal speakers.

I need to find an antenna to do a channel scan on the digital channels to see if the speakers work when watching TV.

I did try plugging in an iPod into the Video 2 RCA jacks on the side and changing the input to Video 2 but did not hear the music from the iPod.

[jaimegmr]

Re: Panasonic TC-42PX14 no sound internal speakers

Digital TV sound comes out through the SPDIF connection but not the TV's internal speakers.
I tried connecting an iPod to both Video 2 (on the side of the TV) and also Video 1, Component 1 and there was no sound through the TV speakers or SPDIF. Does the TV normally digitize analog audio and output it on the SPDIF connection? It seems to only output audio that is already digital.

[Ltank]

Re: Panasonic TC-42PX14 no sound internal speakers

The audio amp is normally supplied 15-18 vdc from PS but that power is for the audio
amp to power the speakers. You already stated that the other low level outputs did not work either. This points to the main board. Try to locate the audio section on the board.
Look for damage or a loss of voltage to the audio preamps. Or could be the main processor on the board.

[jaimegmr]

Re: Panasonic TC-42PX14 no sound internal speakers

Since the only issue with the TV is the internal speakers not working, I have decided to leave it as-is. I have a surround sound system anyway so the internal speakers would never be used.