Need help with FEMTOVERB

[ranchak]

I just finished up the FEMTOVERB project and plug it in and.........  nothing happened. I figured before I drove myself crazy trying use an audio probe I should check my voltages. I am using a 12 volt wallwart, I don't know if this is part of the problem. I have 12v into the 78L05 regulator, but nothing on the output. I've replace the regulator with another one, checked orientation of my electros, resoldered. I'm at a standstill at this point. Any suggestions?

[Marcvv]

I just finished up the FEMTOVERB project and plug it in and.........  nothing happened. I figured before I drove myself crazy trying use an audio probe I should check my voltages. I am using a 12 volt wallwart, I don't know if this is part of the problem. I have 12v into the 78L05 regulator, but nothing on the output. I've replace the regulator with another one, checked orientation of my electros, resoldered. I'm at a standstill at this point. Any suggestions?

Hi Ranchak,

the circuit askes for 9v. I do not know if in this case the 12 v would be too much. You could start using a 9v battery. In my experience it is also not a bad idea to use a (fresh) battery to test a circuit a, if something was mounted wrong the damage will be limted.

With this build the first thing I would check is your soldering.
Soldering the small apckage IC's is really a tricky thing and you easily create a solder bridge between pads that should not be connected. So start there.

After that I would try again and if you still have no signal start measuring the voltages and post them.

Good luck

Marc

[ranchak]

Marc, I have checked all of my soldering and haven't found anything to be faulty. What I did find is that I have no output voltage at 78L05. I have 12v at the input, using a continuity meter I have a good ground and I have made sure that the regulator is orientated correctly. Am I wrong to assume that if I have continuity I have a good ground source? I am assuming that since there is continuity all components between ground and the G of the regulator must be soldered and functioning correctly. It sure would be nice to have reverb!

[Marcvv]

Marc, I have checked all of my soldering and haven't found anything to be faulty. What I did find is that I have no output voltage at 78L05. I have 12v at the input, using a continuity meter I have a good ground and I have made sure that the regulator is orientated correctly. Am I wrong to assume that if I have continuity I have a good ground source? I am assuming that since there is continuity all components between ground and the G of the regulator must be soldered and functioning correctly. It sure would be nice to have reverb!

Maybe you blew the 78L05 as you are getting no output there? Are you sure that there is no short ? 
I always check my soldering with a magnifying glass. Very often shorts or bad solder is one of the problems you encounter whyen debugging.

I am not sure but the circuit is designed for 9v. It is brought down to 5v for the digital IC's.
Did you run it from a battery? Again that is what I would do on testing a new circuit as you will not blow up part so easily.

I just thought of something:
Did you solder the digital IC's on the bottom side of the PCB cause that is where they should go??

Hope this will help a bit.
Marc