School me up Snack Shack

[401waterman]

All my wires are correct, all my soldering are in place (though not great, but no overlapping/touching spots), and my 8 beers drank... Where did I go wrong?

I can play "clean" through my bypass, but I hear the cycle chick. chick, chick, chick, sound. No guitar just a pulse of hum. How easy is it to overheat parts and render them useless? I've checked everything!! Everything! I'd had to start new and wait for new parts in the mail. Any advice? Any help?

I can play clean
Cannot play through the pedal
Only noise when active is a chick-chick-chick-pulse. No guitar noise.
No LED light (bought a pre-made thingy with installed resistor from RadioShark)
My soldering looks OK, not fantastic, but just OK

Any additional pics would help? I'll upload mine right after this post--I have to reduce their size.

Thanks guys! School this noob please!!

[401waterman]

I mean the chick sound after I engage the footswitch...

[401waterman]

Any can show their Snack Shack internal guts for me?

[401waterman]

Yes, I know the wiring is messy...

[401waterman]

I guess I'm just replying to myself...

Update--went to RadioShack and bought a meter reader (DMM), then grabbed a quick burrito. Ate. Rushed home (25 minutes away) to find out the fracking thing needs a 12volt battery. I'm a dunce. Or was I just starving?

Starting all over--yes I bought two pairs of parts and PCB's!

Score: -1 for not grabbing a battery for the DMM, +1 for buying extra parts.

Cheers



An hour later... update. No read across R3 and C5 and C1. Is it easy to burn these out with the Solder iron? Or did I just get bad caps and such from the retailer?

what do you guys think?

[401waterman]

Is this the right one for C1? It's supposed to be a 10n cap. The next spot/point after this is the chain--linked to the output I get a signal... But not through this capacitor! Even with the fresh one I have there's no signal through my DMM... What do you guys think?

[jkokura]

Sorry I missed this one!

I'll have a closer look in the morning. First up though, I can tell you that I think you are using your DMM to do something it can't do. I'll take a closer look and give some suggestions in the morning.

Jacob

[shawnee]

Yes a 103 is a 10n cap and is correct for C1.
You really can't measure a cap with a standard Volt/Ohm meter. Caps aren't really static sensitive so unless you really put the heat to them soldering, they shouldn't be a problem.

If you measure resistance you should get some sort of reading on a resistor but it may not be accurate. If the resistor is connected on both ends it is part of the circuit and other components in parallel will affect your readings.

If you are absolutely sure that everything is wired correctly and you have used the right compnent values, I would suspect the transisitors first. Not all compatible transistors have the same pinout. Which ones did you use? If they are in wrong, you usually get a very weak "gated" splatty sound if anything.

If you aren't getting anything from the LED than something isn't wired correctly though.....

As simple as this sounds, make sure that you have the guitar going to the input jack and not the output. I actually did this on my first build because I am so used to seeing input on the right side and the way I had the board laying put it on the other side.

[mgwhit]

Clicking noises are frequently capacitor-related, but since you can't even get the LED to light up, you really need to start by debugging your power supply.  Your LED either isn't getting the required voltage in the positive side or its cathode isn't properly grounding when you hit the footswitch.  Put your DMM on a low voltage DC setting (I set mine to 20V DC) and measure that you are getting 9V DC or slightly higher at the power jack.  (Note that -9 V DC here is bad.)  I'd be shocked if you aren't, but you gotta check.  If you can check the voltage DC after the LED resistor, do that, too.  I know you're using one of those prepackaged RS LED's, so you might not be able to get to it without taking off the shrink tubing.

Use the continuity setting on your DMM to test for continuity between the LED cathode and ground.  You should only have continuity to ground on one of the footswitch settings.  Your LED cathode needs continuity to ground in order to complete the circuit and light up.  If it doesn't have it in either footswitch setting then it can never light up.

I'm not ready to go there yet, but did you use the transistors from the Bill of Materials or did you use other comparable transistors? One of your transistors has a severely bent leg, it's not shorting out against another leg, is it?

[jkokura]

All my wires are correct, all my soldering are in place (though not great, but no overlapping/touching spots), and my 8 beers drank... Where did I go wrong?

I can play "clean" through my bypass, but I hear the cycle chick. chick, chick, chick, sound. No guitar just a pulse of hum. How easy is it to overheat parts and render them useless? I've checked everything!! Everything! I'd had to start new and wait for new parts in the mail. Any advice? Any help?

I can play clean
Cannot play through the pedal
Only noise when active is a chick-chick-chick-pulse. No guitar noise.
No LED light (bought a pre-made thingy with installed resistor from RadioShark)
My soldering looks OK, not fantastic, but just OK

Any additional pics would help? I'll upload mine right after this post--I have to reduce their size.

Thanks guys! School this noob please!!

I hate to have to say this, and I hope you take this the right way, but don't ever assume anything is correct when you're debugging. Even if you've checked it a dozen times, it could still be wrong and you're just missing something. Sometimes we get in this headspace that what we've done is right, even though it isn't. I make wiring mistakes ALL the time, and if I ever say that for sure my wiring is correct I'd miss the problem! I did this on an early debugging problem when I assumed all my parts were correct. I checked the values more than a dozen times, and each time I missed that what I thought was a 100R resistor was actually a 100K resistor and needed to be changed. So I hate to say it, but my first suspect is your wiring.

Here's my suggestions for a plan of attack:

1. Check out the debugging rules thread here: http://www.madbeanpedals.com/forum/index.php?topic=902.0. That thread will give you the basic approach to debugging.

2. Disconnect the circuit from your switch and jacks. You need to verify that the circuit is working outside of your switching. What I would suggest you do is connect the DC jack and your two 1/4" jacks to the 9V, in and out wires on the PCB. Make sure all the grounds are connected to each other and the PCB. The reason we do this is to eliminate the LED and the switch to get the circuit working for sure. If we know the circuit works, then if there's a problem we know it's the wiring and not the circuit.

3. If you can't do this, then we can debug all of it at the same time. Two useful tools are the DMM it seems you just got, and an audio probe which you can build if you have some time and a radio shack. If you don't have those two tools handy, get them.

4. The DMM has two uses that are important for us - measuring DC voltage and the continuity (Beep) test. one of your comments made it seem like you're checking to see if signal is passing - the audio probe is better used for that. To use the DMM effectively, connect the black probe to ground, and then use the red probe to measure your DC voltage at these places: 9v jack, 9V in pad on PCB, ground pad on PCB, and each of the transistor legs. Other places can be measured, but they're essentially useless for us. Write down the voltage readings you get and post them here.

5. The audio probe can then be use hooked up to your amplifier to see where your guitar signal goes wrong. To use it connect the audio probe to your amplifier, your guitar to the circuit, and then clip the ground wire of the audio to ground. Once it's connected, you can use the probe to start at your in pad on the PCB to begin to trace your audio through the circuit. Having a schematic handy to make notes is handy. If you have signal and then it completely drops out after a part you can usually suspect that part is one of three things: The wrong value, installed backwards, or poorly soldered. It can sometimes be a bad part, especially if it's a transistor, but usually it's one of the three things I just mentioned.

I think that's it for now. Luckily your circuit is really simple. But you asked for some school, and that's what I've got for this morning. Hope it helps, and I'll be waiting to hear back on how you make out.

Jacob

[401waterman]

Thanks everyone!

So instead of doing the smart thing and debugging the circuit. I started to build my second one (assuming my soldering was awful) in hopes it was just "gonna work".

Haha--NOPE! Same issue as before. I get bypass guitar sound but when the footswitch is engaged still that clicking...

Off to the shack to get more parts for my audio probe.

I'll give you an update in a few hours.

[401waterman]

So I borrowed my dad's OLD meter... What the frack setting do I use?

I get a reading when I connect ground to the transistor legs. I've been using the Check setting--I think you guys call it the continuity test. This meter is old enough it doesn't beep.

I did test the ground to the positive in on the PCB and passed the Check. I touch the transistors and they pass the Check.

[shawnee]

It looks like the diode is in backwards in both pics. Turn them around on both boards and see if that does it.

[401waterman]

Does that mean Madbean got his backwards too? I looked at the original pic on this thread...

http://www.madbeanpedals.com/forum/index.php?topic=69.0

[shawnee]

Who are you going to trust, me or Madbean? 
Man I can't explain that because the layout shows it the opposite way. I am not the guru that the other guys that are helping are. Maybe swap it around on one and see since it's pretty easy to do.....