Welcome to the board!
As far as testing the TDA2822M, the
datasheet (google "TDA2822M datasheet"--this works for most commercially available components, by the way) contains a very simple circuit which you can build to test the chip. Figure 16 in the datasheet shows how to wire it to headphones.
[Edit: if the IC is in a circult and you have access to an oscilloscope you can just probably compare the signals at the inputs and outputs. I think you may need a dummy load resistor to do this though--some of the more experienced members would probably have the last word on this.]
Regards,
Torben
[Obligatory netiquette note: it's bad form to hijack a thread to ask your own question. Also, this thread has been dead for two years.
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