Blue Clipper issue

[snakey]

I've finished soldering up a blue clipper and shes a no goes. works fine when bi-passed but not when run threw the circut. i've probed the ic pins and i'm getting really low voltages, less then 1v, from all the pins except the power pin which is its proper 9.8v. My diodes have absolutely no vollts which is pretty much consistent with the rest of the circut. Is the ic stuffed? i'm not using an ic socket its soldered directly to the board. thanks

[StereoKills]

Read the Debugging Thread that is stickied. That should get you started in looking for problems and posting all the necessary information for us to help. Judging from the little info you provided though, I would make sure everything is soldered properly, pin 7 at least should have a direct connection to V+ (your 9.8v).

[snakey]

i apologies i completely forgot about the  putting the schematics and stuff. i read the debug section before posting too .

Name: Tonepad Blue Clipper.
Schematics: http://tonepad.com/getFileInfo.asp?id=93
Issue: No sound when effect is on.

Pin 7 has positive +9.8v
Pin 4 has -9.8v
the rest have less then 1v
diodes 0v
i have checked all soldering with continuity tester and its all making a conection.

[Cardboard Tube Samurai]

Check your earthing/grounding. Low/no voltage anywhere in the circuit says "short to ground" to me

[StereoKills]

Pin 4 should be 0v... Keep in mind when using the multimeter that the black lead should always be on ground when taking voltage measurements.

[snakey]

i've check all my soldering for shorts with a continuity tester and they are all good. Pin 4 has 0v when i have the black lead on earth and probe it. when i put the red lead to power and pobe pin 4 it has 9.8v. like it should being directly connected to earth. i've found a loose resistor so i've resoldered and testing when i get home from workies

[snakey]

mmm didnt fix it. would someone be able to give me the voltage before and after c1 please. i've got nothing before and 1.5 after. i should probably also mention that i had to put the ic in upside down with the pins bent around. i didn't invert the board when printing it onto the pcb and i used a 250k resistor instead of the 240k. and some random diodes i had lieing around thank you.

[Cardboard Tube Samurai]

Try using the correct diodes and triple check the orientation of everything

[snakey]

ok changed the diodes. still no workies. thanks for everones help thus far.

[petemoore]

  9V >10k {{*}} 10k> Gnd. [0.0v]. A voltage divider is two equal value resistors forming a series circuit across a power source.
  I chose 9vdc battery, and assigned ground as 0.0vdc.
  The two resistors divide the 9v voltage equally, 50/50, therefore, {{*}} will be "1/2v" [half the value of the supply voltage], also called Vbias or other.
  For equal voltage dividing [50/50] the two resistors can be any value, finding the resistive voltage divider is then: two equal value resistors strung across the power rails.
  1/2v provided by the voltage divider is what assigns the operational voltages of the opamp. Test for 1/2v at the voltage divider resistors, if supply is 5v, this would be 2.5volts. Don't assume though, use and measure a fresh 9vdc battery before and after it is connected to the circuit, right after checking the circuit's battery clip to verify the battery won't be shorted out if connected. If shorting condition occurs at the battery clip, eliminate it before applying power.
  Say we have all/every ground-node measureing 0.0volts from ground, and haven't assumed 9v supply, we've measured it with the circuit connected and loading it.
  Move to the V-divider and active device pins, meausure them as the debugging page details.
  If the voltages look operational and all grounds are grounded, audio probing is a good next thing to try, as well as searching for a stray ground or very low resistance between the signal path and a power rail [ground and V+].
 
 
 

[Cardboard Tube Samurai]

Maybe try posting pics and schematic etc along with the advice in the debug thread

[snakey]

hmmm there isn't 2 identical resistors in the schematic. and there isn't any 4.5v tracks. everything except the power rail is less then 2 volts.

cardboard: look up ^ relevant information is there.

[Cardboard Tube Samurai]

Have you double/triple checked the orientation of caps C2, C3 and C5? Have you adjusted the trimpot at all? What switching method have you used? A picture speaks a thousand words

[snakey]

mmm a pic would be good. i'll see if i can rustle up a camera and get a shot of the board up

[snakey]

Fixed! ic was faulty. works a treat now