I've narrowed down the problem on my TV, but I need some help reading
a schematic. What do solid black arrows with values next to them
pointing to inputs/outputs mean? There are no units (V, Ohms
etc.)beside them, so I'm assuming they are DC volts?

I'm pretty sure that the main speaker amplifier is defective, but
before I go through the process of ordering another one, I would like
to confirm that the supply voltage is present. On the IC it shows a
value of 21.5 with a solid black arrow pointing to VCC, can I assume
that I should have a reading 21.5 VDC at this pin?

That would be my assumption, in a properly functioning circuit. Check for
general notes on the schematic, i.e. ' all values shown in DC volts unless
specified '.

On the IC it shows a
value of 21.5 with a solid black arrow pointing to VCC, can I assume
that I should have a reading 21.5 VDC at this pin?

Why not take a voltage reading on a part of the TV that's working
correctly and compare it to the schematic.

Degull wrote:
I've narrowed down the problem on my TV, but I need some help reading
a schematic. What do solid black arrows with values next to them
pointing to inputs/outputs mean? There are no units (V, Ohms
etc.)beside them, so I'm assuming they are DC volts?

I'm pretty sure that the main speaker amplifier is defective, but
before I go through the process of ordering another one, I would like
to confirm that the supply voltage is present. On the IC it shows a
value of 21.5 with a solid black arrow pointing to VCC, can I assume
that I should have a reading 21.5 VDC at this pin?

Degull wrote:
I've narrowed down the problem on my TV, but I need some help reading
a schematic. What do solid black arrows with values next to them
pointing to inputs/outputs mean? There are no units (V, Ohms
etc.)beside them, so I'm assuming they are DC volts?

I'm pretty sure that the main speaker amplifier is defective, but
before I go through the process of ordering another one, I would like
to confirm that the supply voltage is present. On the IC it shows a
value of 21.5 with a solid black arrow pointing to VCC, can I assume
that I should have a reading 21.5 VDC at this pin?
Those are voltages and are DC. There will also "TP"s on these boards
that are test points for crucial voltages.
Could you give a more extensive description of your problem? What's the
model #? Is there no sound at all? Is it tuning properly? Is there
sound on the line outputs? There is a common problem with Sonys of a
certain type where the sound just goes out or gets really flakey but
the line output is unaffected.
Look for "Sony KV-32TS35 No Audio" in this same forum, posted Dec 30. I
actually had one like that and bought the part from Mats. Works fine.
Very satisfying.
Richard

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.

Sounds like maybe the internal speakers are in the OFF
postion in the Menu,s.
Did you check the Menu,s ?



"Degull" wrote in message
...
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.