dtmf decoder circuit trobleshooting

[pallavishr91@gmail.com]

i have made a dtmfdecoder circuit on pcb bt its nt working is there any way to check it correctly???

 

[crutschow]

You check the signal at each of the circuit nodes and determine which is not correct.

Without a circuit diagram I can't comment further.

 

[pallavishr91@gmail.com]

this circuit i have used

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this circuit i have used

 

[betwixt]

Some problems:

1. you do not need C1 and C2.
2. Check the crystal is 3.579MHz
3. R4 & R5 are shorted out
4. any reason why R4 and R5 are in parallel?

Please tell us the component values you are using.

Brian.