The TV is a Sony KV-32TS35. The video works fine but there is no audio. I tested the audio outputs at the rear of the TV with a pair of computer speakers and they work fine. I have been using a schematic for a Sony KV-27TS35. The audio and tuning sections in the KV-27TS35 look identical to what I have in my KV-32TS35. After following the audio path in the schematics it looks as though the audio is split to two areas once it is processed in the SBX1637 sound module. The SBX1637 feeds the audio outputs at the rear of the TV on the A board and the main speaker amp on the B board. I'm assuming that because I have audio at the audio output on the rear of the TV, the audio output of the SBX1637 must be good. I checked the voltages on the main amp which is a TDA2009A chip and they all match the values on the schematic except the for the outputs of the chip which are 0 VDC (they should be 10.7). It looked as though the TDA2009A chip was bad. So I managed to find the TDA2009A at local electronic supply (the only one they had) and I replaced it. Damn it, still no audio? The new chip tested the same as the original chip with all the voltages matching the schematic except for the outputs which were still 0 VDC. I'm wondering if I got a bad chip? It was the electronic store's last TDA2009A.
I read somewhere that I should be able to test the inputs of the main amp IC by using a pair of amplified computer speakers? This will tell me if the audio signal is reaching the amp IC (TDA2009A). The inputs of the amp IC read 1.4 VDC as shown in the schematic but I'm not sure that means that audio is present.
I thought I had it licked with a new TDA2009A, but I guess not.