TDA7294 - no output

child1

Member
2013-01-18 7:24 am
Hello... :)

I have been building a subwoofer plateamp based on the TDA7294 chip. I have read a lot about the chip on this page and others, but haven't found the reason for my problem still.

There is simply no output from the amp! Only a vague humming noise from the speaker when i put my ear very close to it. Flipping the mute and stndby switches dosn't seem to change the humming.

Measurements:
V+ = 32.8V
V- = 32.9V
Mute/stndby pin both > 25V
No DC offset on output

So what can it be? I have attached a schematic and PCB drawing

Please help !

-Mads
 

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