Im trying to make this circuit then use a N1208 nokia Cellphone as the tone source. I putted a LED to each output to see whats going. It worked at first but without Q2 ouput going high. I dont know why its not working, I checked it with the Volt Meter and it gives me .5V reading. Other outputs work properly only the Q2 is not. When I rechecked I found out that I mistakenly connect the .01uF at pin 17 to the ground instead of connecting it to the voltage source.
I then fixed the wrong connection and try to rerun it again. Here comes another new problem the whole thing is not working. All the output doesnt change state when numbers are pressed and the Q2 pin still on low.
Oh god did I just wasted my 10$ for this decoder? can this problem still be fixed?
Help me please. I ordered this chip from other country and waited 5 days just to destroy it.
**broken link removed**
I then fixed the wrong connection and try to rerun it again. Here comes another new problem the whole thing is not working. All the output doesnt change state when numbers are pressed and the Q2 pin still on low.
Oh god did I just wasted my 10$ for this decoder? can this problem still be fixed?
Help me please. I ordered this chip from other country and waited 5 days just to destroy it.
**broken link removed**