Help debugging. I have some questions.

[elenore19]

Debugging.

1.   Name of project: EF440 from General Guitar Gadgets
2.   Links: http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=119&Itemid=26
3.   I followed the layouts exactly. These are the best pictures I have.
4.   I did not substitute any parts in. I used exactly what I was given.
5.   No battery clip. Not sure how to tell.
6.   When clicked on...the LED comes on, but no sound. All I hear is a very apparent crackling that sort of got worse when I messed with the volume knob. My playing on the guitar had no effect on the sound as far as I could tell.
I don't use battery clip. I use a one spot multi pedal power deal, and it works with all my other pedals, so hopefully that means we can rule out a faulty power supply...but I could be wrong.

So I'm new to using multi-meters.
I have an Equus 3320 auto-ranging digital multi meter.

I put the setting to the "10 MegOhm input DCV". I also tried the "DC/MA" and the "DC10A."
It looked like I was getting pretty consistent results with the first one, so I stuck with it. (?)

In the debugging thread, it said to list it as "Q1, Q2, etc." and then list the "C, B, E" for each.
First debug for me, so I'm new. Work with me...
First, the Q1's Q2's... transistors, right? As far as I can tell, there are no Transistors in my pedal...
That being said... I did some measurements on all the resistors. I ended up with some really strange readings, that made me think that I was doing something wrong, so I measured a couple capacitors and then decided to consult with you guys before I did everything else in case I'm doing something wrong. (Which I suspect I am)
So here are my readings...I have them setup as "Resistor/capacitor number - labeled resistance - lead number (left 1, right 2, or bottom 1 to top 2 if you're looking at the diagram on GGG) -> Reading." I found a couple of readings, (actually more than a couple) to be measured and then start at around 80mV and slowly go down and never settle. I recorded the number that was most consistent in that down fall...

R1 - 10k
1 -> 8.3V
2 -> 8.31V
R2 - 100k -
1 -> 8.31V
2 -> 6.91V
R3 - 100k -
1 -> 6.92V
2 -> 4.9V
R4 - 10k -
1 -> about .9V (NS=never stopped on one number?)
2 -> about .9V (NS)
R5 - 2.2M -
1 -> about .89V (NS)
2 -> about .85V (NS)
R6 - 2.2k -
1 -> .933V
2 -> .933V
R7 - 22k -
1 -> 9.16V
2 -> 4.96V
R8 - 22k -
1 -> 0.2mV
2 -> 4.96V
R9 - 220k -
1 -> 4.96V
2 -> 8.37V
R10 - 220k -
1 -> 8.37V
2 -> 8.19V
R11 - 220K -
1 -> 8.41V
2 -> 6.96V
R12 - 430K -
1 -> 8.4V
2 -> 8.19V
R13 - 100k -
1 -> 9.16V
2 -> 4.87V
R14 - 22k -
1 -> 0.2mV
2 -> .933V
R17 - 1k -
1 -> 9.16V
2 -> 1.856V
R18 - 1.5M -
1 -> 0.1mV
2 -> 0.1mV

C1 - 0.01uf -
1 -> 8.37V
2 -> 0.1mV
C2 - 0.1uf -
1 -> 0.2mV
2 -> 9.15V


Hopefully someone can point me in the right direction.

-Elliot
Please let me know what other pictures I can take for you, I'm in the process of trying to get a hold of a better camera.
These are the best I have for now.

UPDATED: I tried to disassemble my pedal a little just to check out anything and everything...a mess, I know. (my 2nd build)

[arma61]

Hi

yes, no transistor here but IC, and you should misure voltages at IC1 pins, DMM black probe to ground then poke with the red one on every pin of IC1

IC Pins orientation
1♦    8
2     7
3     6
4     5

these are the voltage from GGG
Pin 1 4.34v 
Pin 2 4.30v
Pin 3 4.37v
Pin 4 0v
Pin 5 4.30v
Pin 6 4.37v
Pin 7 4.36v
Pin 8 8.7v

Cheers
Armando

[flintstoned]

Double check your 9v jack wiring!

[elenore19]

Hi

yes, no transistor here but IC, and you should misure voltages at IC1 pins, DMM black probe to ground then poke with the red one on every pin of IC1

IC Pins orientation
1♦    8
2     7
3     6
4     5

these are the voltage from GGG
Pin 1 4.34v  
Pin 2 4.30v
Pin 3 4.37v
Pin 4 0v
Pin 5 4.30v
Pin 6 4.37v
Pin 7 4.36v
Pin 8 8.7v

Cheers
Armando

Here are my IC readings.
IC1
1-?
2-?
3-5.87v
4-0
5-8.37v
6-8.39v
7-8.18v
8-9.16v

The ?'s on 1 and 2...When trying to read them it started around 1.6v and then slowly kept going down, never settling at all on any number. So not sure about that...
And then pretty much all my other readings were off of what GGG said they should be.
What's this mean? Next step?

Double check your 9v jack wiring!

There is one cable that I had to remove haphazardly...not sure why anymore, but it's just sort of on there where I Would hook up a battery clip. But I don't use batteries. Otherwise it looks like the layout said it should.
I just realized that those pictures were of the original problem...which was wiring with the 9v jack! So I'm uploading new photos right now. Good call.

[flintstoned]

Im still a noob but i dont see any kind of polarity protection in the circuit. The chip might not like 9 volts straight into ground!

[elenore19]

Im still a noob but i dont see any kind of polarity protection in the circuit. The chip might not like 9 volts straight into ground!

I'm not sure what you're talking about.
The chip is in the PCB and the pcb is hooked up to the ground how the layout showed it to be.
Could you elaborate please?
No disrespect of course. Just confused.

[flintstoned]

I was referring to when you had the dc jack wired backwards, did you power it up? sending 9v+ to all ground connections?

[jkokura]

First thing to check is your wiring. That's usually the problem on *most* of my builds. I say most because that's usually the easiest part to get wrong. Go over it, then go over it again.

Next, for future reference, while it's nice that you posted all the resistors and cap numbers, usually all we need are diode, Transistor (Q), and IC numbers. It's important to understand the way IC numbers work (see above post).

Third, welcome to the world of building! It's frustrating to debug, but it's a big part of the process.

Lastly, I would triple check your wiring. If that's not the issue, then check the orientation of your caps, diodes, IC's and Transistors (none in this project?) making sure they are the right way around and soldered in properly. Check all the solder points and make sure they are well soldered (check the wiki above for details about building tips). Make sure you have installed any jumpers and haven't left out any parts. And finally, if all that is working right - get out a DMM and begin to check all the wires and solder contacts to make sure you have connectivity (beep test, google it if you don't know how). All of this is pretty easily done if you have an Audio Probe. It made my life debugging a LOT easier.

jacob

[caspercody]

Looking at your pictures, the three prong jack that is your inout jack?

If so, there does not look to be any wire on your tip connection, which would be your input. To me it just looks like your ground is connected. Look at this wiring?

Also look at your output jack. Looks like you have the tip wired to the ground on your input jack?

[caspercody]

Sorry, maybe the output jack is fine. Those two yellow wires look cofusing at first glance.

But I still think you need to look at the input jack.

[elenore19]

I was referring to when you had the dc jack wired backwards, did you power it up? sending 9v+ to all ground connections?

Yes.
I figured that destroyed some things... Is it for sure you think? I do remember smelling a faint burning smell when I had the ground messed up...But usually that comes from my lamp, so I sort of passed it off...BUT. Yeah...
I'm thinking I might just salvage the switch, pots, and jacks and what not and use them for another project.
But we'll see..

First thing to check is your wiring. That's usually the problem on *most* of my builds. I say most because that's usually the easiest part to get wrong. Go over it, then go over it again.

Next, for future reference, while it's nice that you posted all the resistors and cap numbers, usually all we need are diode, Transistor (Q), and IC numbers. It's important to understand the way IC numbers work (see above post).

Third, welcome to the world of building! It's frustrating to debug, but it's a big part of the process.

Lastly, I would triple check your wiring. If that's not the issue, then check the orientation of your caps, diodes, IC's and Transistors (none in this project?) making sure they are the right way around and soldered in properly. Check all the solder points and make sure they are well soldered (check the wiki above for details about building tips). Make sure you have installed any jumpers and haven't left out any parts. And finally, if all that is working right - get out a DMM and begin to check all the wires and solder contacts to make sure you have connectivity (beep test, google it if you don't know how). All of this is pretty easily done if you have an Audio Probe. It made my life debugging a LOT easier.

jacob

Thanks for the welcome!
I've checked my wiring going on 20 times now. So hopefully I'm not that blind
I just checked the orientation of all those parts. I was EXTRA careful with that when putting it together.

As I replied to flintstoned, I believe I definitely have fried at the very list the chip. If not other things.

I'm thinking of salvaging parts and using them for another project. Or should I not give up yet?
I did connect the ground wire to the power input (not sure of terminology) so basically power was going everywhere it really shouldn't have been. Or at least in a lot larger quantities than it should've been.

Thanks for the help though, it is appreciated.

Sorry, maybe the output jack is fine. Those two yellow wires look cofusing at first glance.

But I still think you need to look at the input jack.

Yeah, I checked it and it looks fine according to the diagram and the other pedal that I built (and works!) has the wires the same way there. But thanks for the advice.

I've pretty much decided that I'm going to salvage what I can from this..mainly pots, jacks, and switch and use them towards another built that I'm lookin' into.

Thanks for everyone's help.

[flintstoned]

Don't scrap it! Caps and resistors are still good, even the led. Just get a new chip when you order parts for your next project. Noob advice: always order an extra chip and transistors! Those are the parts that get hurt from mistakes. There will be mistakes!

[JKowalski]

Don't scrap it! Caps and resistors are still good, even the led. Just get a new chip when you order parts for your next project. Noob advice: always order an extra chip and transistors! Those are the parts that get hurt from mistakes. There will be mistakes!

Seconded. Don't do it! Looks to me like all it will take is pulling the IC out of the socket and sticking a new one in, a good two seconds, and it will prob be fixed.

[elenore19]

Don't scrap it! Caps and resistors are still good, even the led. Just get a new chip when you order parts for your next project. Noob advice: always order an extra chip and transistors! Those are the parts that get hurt from mistakes. There will be mistakes!

Don't scrap it! Caps and resistors are still good, even the led. Just get a new chip when you order parts for your next project. Noob advice: always order an extra chip and transistors! Those are the parts that get hurt from mistakes. There will be mistakes!

Seconded. Don't do it! Looks to me like all it will take is pulling the IC out of the socket and sticking a new one in, a good two seconds, and it will prob be fixed.

Alright...I already had started the disassembling.
But I'll definitely look into a new chip and work on gettin' it up and running.
Could the diodes have gotten hurt as well? or should they be fine? if I'm orderin a chip, I want to make sure there's nothing else to get with it.

Thanks again for all the help!

-Elliot

[jkokura]

I blew a diode in a build by having it installed backwards. Essentially, my power was leaking to ground because the diode was in backwards. This blew the diode, so when I turned it around, power wasn't getting to ground anymore, but it still wasn't working. Replaced the diode and everything was fine - no other parts of the circuit were damaged. So yes, if the diodes were in backwards, they could have been damaged. The only way to truly check it out would be to see if you can get them into a working circuit. If the circuit still works you're good to go, but if not then the diode is blown.

I don't ever give up on circuits. I have some that I've stepped back from for a long while, but never give up.

Jacob