TDA7052 - No sound

Discussion in 'The Projects Forum' started by vol_, May 5, 2016.

  1. vol_

    Thread Starter Member

    Dec 2, 2015
    Hello everyone,

    I'm working with a TDA7052 circuit. The schematic is shown below:


    I've build the circuit with TDA7052A (that has a dc volume control on pin 4) before, instead of TDA7052, and everything was ok. But now i'm not getting any sound output in the speaker. The speaker just moves because of voltage (i dont have other words to describe this) and stays there. What is weird to me is that the voltage on pin 5 is 4.5V and on pin 8 1.3V. I'm suppling the circuit with 6V from a commercial transformer?

    My opinion is that probably the chips are fake, although they look genuine from the outside. Good printings and so on. Or maybe they re old. They are Philips and not NXP. I hope i'm wrong because i purchased 15 of them.

    Any thoughts?

  2. vol_

    Thread Starter Member

    Dec 2, 2015
    Oh, also it overheats. The speaker impendance is 8R. And i supply the circuit with 6V, as i mentioned before.
  3. bertus


    Apr 5, 2008

    As you describe, it looks like there is DC on the input.
    What is the DC voltage at pin 2?
    Is C1 ok?

    vol_ likes this.
  4. vol_

    Thread Starter Member

    Dec 2, 2015
    I had connected R3 at the front side of C1 (near to the MPF102), because thats the way its connected in TDA7052A. That was my mistake. In tda7052 is connected at back side of the C1 (near to IC).

    Thanks for givin me this knowledge about the DC voltage at the input!

    Cheers mate!