Curtis 3227A no Audio Issues

[budm]

Re: Curtis 3227A no Audio Issues

Can you read the schematic? You also need to understand how that IC functions when it used in SE (Single Ended mode) and why it needs the DC blocking/coupling cap.
The output pin of the power amplifer will sitting at 1/2 of the supply VCC, so if the power supply is 24VDC, then the output pin will be at 12V.
As you see, if you hook up the speaker directly to the output pin of the IC, then you will be applying 12V to the speaker which you will damage the IC and the speaker, that is why you need the DC blocking/coupling cap between the output of the amplify and the speaker.
if the has leakage resistance or shorted out then the cap will no longer block the DC to the speaker.

If you trace out the + speaker wire to see if it is connected to one end of the cap, and another end of the cap goes back to the amplifier output or not. See PDF page 19 FIGURE 32 as a guide.
you need to look at the spec sheet of the IC, then trace out the connection from the output pin of the amplifier all the way to the speaker connector.
BTW, if you have 12VDC on the speaker terminal with the speaker connected then you have heard loud popping sound form the speakers.
You should check the speakers if they are still OK.

Notes: the amplifier in your TV is the Class D amplifier, the example below is the Linear amplifier but the outputs for both type of the amplifier with single power supply will have DC at the output, the DC blocking cap is also part of the high pass filter, see PDF page 14.
http://reviseomatic.org/help/e-a-amp...Amplifiers.php

[Diah]

Re: Curtis 3227A no Audio Issues

I did look for the obvious as to whether the internal speakers were on or off, I am presently using the rca audio jack to run from a dvd player.

trouble shooting the sound by using out source audio signal more complex as TV signal as there many circuit switcher & main IC Digi signal detector / switcher.
also to make it easy , first make hard reset for the TV, and plug it to RF signal as TV and make first install and Chanel search.. from this point we will have narrow the circuits involved with sound issue.

[martino]

Re: Curtis 3227A no Audio Issues

trouble shooting the sound by using out source audio signal more complex as TV signal as there many circuit switcher & main IC Digi signal detector / switcher.
also to make it easy , first make hard reset for the TV, and plug it to RF signal as TV and make first install and Chanel search.. from this point we will have narrow the circuits involved with sound issue.

You really need to work on your English or use something better then Google translator,I am trying really hard not to dislike you here.

[mike123333]

Re: Curtis 3227A no Audio Issues

Can you read the schematic? You also need to understand how that IC functions when it used in SE (Single Ended mode) and why it needs the DC blocking/coupling cap.
The output pin of the power amplifer will sitting at 1/2 of the supply VCC, so if the power supply is 24VDC, then the output pin will be at 12V.
As you see, if you hook up the speaker directly to the output pin of the IC, then you will be applying 12V to the speaker which you will damage the IC and the speaker, that is why you need the DC blocking/coupling cap between the output of the amplify and the speaker.
if the has leakage resistance or shorted out then the cap will no longer block the DC to the speaker.

If you trace out the + speaker wire to see if it is connected to one end of the cap, and another end of the cap goes back to the amplifier output or not. See PDF page 19 FIGURE 32 as a guide.
you need to look at the spec sheet of the IC, then trace out the connection from the output pin of the amplifier all the way to the speaker connector.
BTW, if you have 12VDC on the speaker terminal with the speaker connected then you have heard loud popping sound form the speakers.
You should check the speakers if they are still OK.

Notes: the amplifier in your TV is the Class D amplifier, the example below is the Linear amplifier but the outputs for both type of the amplifier with single power supply will have DC at the output, the DC blocking cap is also part of the high pass filter, see PDF page 14.
http://reviseomatic.org/help/e-a-amp...Amplifiers.php

When I viewed the spec sheet I did not look at the schematics further down to see the circuit layout. I did trace back the connection from the speaker to the cap and cap to the IC, they were all good.I double checked the capacitance and the ESR on the caps they were good and no shorts.

In the process of removing the speakers and checking the functionality of the speakers I was having a little bit of trouble at first getting them to function with the wire connection, even with trying to get a good resistance read. I finally tested them offline and they both worked. I then placed the main board back into the TV and lo and behold they both worked. I thought at this point maybe there is bad connections(cold solder joint) on the speakers so I applied solder and reworked that in there.

It turns out that this particular model does not have an audio out I was more referring to a second gen of this model manual instead of looking at the back panel and the description of the inputs and outputs. . So I am wondering now whether that is the issue with the speakers and cold solder joints or bad connections. At least now I understand that part of the circuitry.Thanks to every ones help....

We will have to see how long they remain operational.

[budm]

Re: Curtis 3227A no Audio Issues

So your TV does not have RCA audio line outs as shown in the owner manual that I found for your TV.
Just keep an eye on it then and see what happen.

[mike123333]

Re: Curtis 3227A no Audio Issues

So your TV does not have RCA audio line outs as shown in the owner manual that I found for your TV.
Just keep an eye on it then and see what happen.

This particular TV I acquired from a friend. I downloaded the manual and kind of used that as my main go to regarding cabling. So when I got the speakers to work I looked at the layout of the inputs on the TV cover and then realized there is no audio outputs.

After I thought more about it regarding the no audio now it makes sense to me about the lack of resistance from the speakers as I was troubleshooting and getting the 12V across the speaker terminal plugs. The speakers were not making good wiring contact.