TDA7294 - no output

[child1]

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

 

[gmphadte]

Are you sure your V- is 32.9 volt and not minus 32.9 volts. Could be just typo but I should confirm.

Gajanan Phadte

 

[child1]

Yes, sorry it is of course -32,9 🙂 just a typo

 

[child1]

Well... it turns out that it does indeed work. Apparently the output from my soundbar project to the sub is either to low or not existing at the moment. So I will have to look into that instead.. :S