Outrageous Moments in Debugging...

[jacobyjd]

So I picked up a populated Great Cheddar board not too long ago, and tonight was the night to do all the offboard wiring and maybe box it up.

As [almost] always, I ran the in/out/power leads onto my breadboard setup to test outside the enclosure. It didn't work on the first try.

Ok, no problem--time to break out the meter and see what's going on. First, let's check the battery voltage (looks good), then start measuring all the crucial points. Huh. 0vDC on everything...well.

Let's check all the 9v connection points--huh. 9vDC before the protection diode and 0vDC after. Weird. I wonder if the diode burned out from reverse voltage (since I don't know where this thing's been). Easy enough to check...

Let's bypass the protection diode--clip either end of an alligator lead on either side of the diode on the component side. Weird...same result. I wonder if something is messing up the voltage AFTER the diode--solder bridge perhaps...

Let's check for solder bridges! Magnifying glass? Excellent. Found one. Test the voltage. Same.

$*%&$(*)&%($(@&(*@&$)(*)(@*$)&()*

*composure*

Let's re-melt all the solder joints--wait, what's that!? A BROKEN TRACE BETWEEN THE 9vDC INPUT WIRE AND THE DIODE!? Brilliant!!! Solder wire directly to the leg of the diode.

SAME $(*#ING problem!?!?!?

All right. Time to bring in the big guns. Let's rip that diode outta there.

Oh.

How about that.

The positive leg of the diode was broken inside the through-hole, and now the 9v trace is broken. Awesome.

Run a jumper to bypass the broken trace, ignore the protection diode, reconnect it all.


Success. Sweet, sweet success.

I feel like a starvnig man who just fell into a vat of spam. This thing sounds glorious.

This is why we DIY, people. To scream profanities at a piece of fiberglass long enough to get something to sound cool.

Next stop, Populated Tremulus Lune board. Here's hoping it's up and running sooner than this Mammoth Munster.

[R.G.]

Good work. As Arthur Conan Doyle said through Sherlock Holmes' virtual mouth, eliminate the impossible and whatever remains, however improbable, must be the truth.

[oldrocker]

Great feeling to get a pedal working after struggling to debug it.  The crazy thing for me is on some pedals I enjoyed the debugging as much if not more than the actual finished project.  In other words I seemed to enjoy the journey as much as getting there.  There's a good feeling when you solve problems just as much as building something.  Good job. 

[R.G.]

Great feeling to get a pedal working after struggling to debug it.  The crazy thing for me is on some pedals I enjoyed the debugging as much if not more than the actual finished project.  In other words I seemed to enjoy the journey as much as getting there.  There's a good feeling when you solve problems just as much as building something.  Good job. 

You, sir, are a confirmed addict.

Welcome. 

[jacobyjd]

Yeah, I have a renewed interest in getting a few semi-abandoned projects off the ground. I figure I'm a little better at debugging than I was before yesterday, and it's likely to get a bit easier from here, given the situation (how often is it that a part actually goes bad vs. some other issue? Hah!).

[R.G.]

Yeah, I have a renewed interest in getting a few semi-abandoned projects off the ground. I figure I'm a little better at debugging than I was before yesterday, and it's likely to get a bit easier from here, given the situation (how often is it that a part actually goes bad vs. some other issue? Hah!).

There is a series of humps to get over in the path progressing from "Which end of the soldering iron do I hold?" to "Well, you see that could only be possible it does this and not that, so therefore this is what's wrong."

You have already surmounted several of these, and you're on the crest and about to start down the other side of a big one.

Good work!

[momo]

Alright!...now you got me all charged up to attack and try to debug once again a vibratone of mine.....boy I can,t wait to hear it work.

[robertreynisson]

I have a couple of disasters that I could mail to you in case you are running short of debug candidates

[jacobyjd]

I have a couple of disasters that I could mail to you in case you are running short of debug candidates

No, no, please!!!     

[nick d]

I just got back into building stuff after a break of ..about 15 or 16ish years. Things that used to be automatic became -"What do I do next?".
          My first trial run - something simple -(Thinks me ) an op-amp BMP from Gaussmarkov. Got the parts together , worked out Vero , re-learned how to solder etc. Spent 2 weeks of spare time doing what used to take 2 hours - connect supply , check supply voltages etc. OK , no smoke! put IC's in , still OK plug in guitar and amp - SILENCE!!
  AH I see it! Supply ground is to case , circuit ground is to lid , which is not screwed on. So I screw it on- more silence - lid off - swear , scratch head , look... get out DMM ..no ground to output jack - 1 wire in now , fixed! NO!!!  Open box again , look, poke , prod - occasional burst of cool sounds from amp - look again - a tiny whisker of screening shorting out on  output to vol pot - fixed!!!!!  45 mins of mindless 3-chord thrash!!!
          I used to think I knew it all.But , as an effective newbie , I discover that you should take nothing for granted . Check everything as you go , double-check it , then check again. Never assume anything! An extra hour spent whilst building could well save many more later!
          Current job is EchoBase - I am proceeding very slowly and carefully. Fingers crossed , I will report soon on a successful build!

[PRR]

> huh. 9vDC before the protection diode and 0vDC after.

Huh. I thought this was leading into my most memorable debug.

Except it was 36V 1A for a factory-bought near-new broadcast console.

This was student-radio days.

Power supply failed (they used to do that). Took it to my bench and had it working in an hour.

Took it back to the console, connected the red and black wires.... shut right down.

I cut the backup console over so the DJs could do their things.

Re-examined my work. Ran the power supply on multiple dummy loads. Re-examined the console for shorts. Cut power bus so only one module was involved.

It took a full MONTH to find the problem.

The whole time the "main" console was off-line. The backup console baffled operators (it was too much machine for what they needed).

I plead youth, and classes, and other stuff, but debugging that power problem really bugged me.

Some stoned-doper wandered in, and asked which wire was red or black. I was explaining the convention, when it hit me........

[g-sus]

I recently had a fight with a tube od project...weird popping and dc problems.

After a looot of debugging (replaced all caps, switches, jacks, wires, redid the whole circuit board) finally found out it was a BROKEN TUBE SOCKET!!

I never ever had thought that a socket can be broken 

[geertjacobs]

I just fixed a half-working Vox V847 Wah after various attempts to fix it over the past two years.
It mostly acted as volume pedal instead of a wah.

Turns out that the zero ohm resistor next to the fasel had one leg that wasn't soldered properly.
Nearly impossible to spot.
Found it by wiggling the components.
Resoldered it and fixed!

[BoxOfSnoo]

There is a series of humps to get over in the path progressing from "Which end of the soldering iron do I hold?"...

...um so?  Are you going to let us in on the answer to this one?

[azrael]

^We'll have to wait for the next "Technology of the..." article! 

[oldrocker]

Yes R.G. you're so right.  I almost get high on building them darn pedals.  My wife thinks I might need to see a doctor.   I've built 100 plus pedals now and have room dedicated to them.  All are working and of course debugged.  I had to stop for a while to see if I still remember how play guitar. lol

[dschwartz]

Talking about outrageous debugging..
few weeks ago i wanted to record some sound samples of one of my pedals (these samples: http://dsmnoisemaker.blogspot.com/2010/05/audio-samples-mas-decentes-del-texas-b.html) and my multicabsim prototype started working intermitently..

i opened and check for loose wires or cold solder joints, the thing was completely random..so i resoldered all ofboard connections..the same....
i just sit with the guitar ringing and moved the board around.. sound-no sound-sound-no sound..aaargghh..then after a while, it started sounding consistenly.. i wrapped it up, prepare to record, and again..no sound...took a deep breath....sat back down, and reopened it..no sound..got closer, sound...moved a finger, sound, pick up the guitar, no sound....then........
i felt my blood flowing through my face, i just could not take it anymore..i started banging the damn thing agaist the ground hard, and harder, then i grabbed the pcb with mi hand and literally eviscerated the poor thing like a madman, screaming words that would make a convicted man blush.. it ended up completely broken..the enclosure was safe though..
I ussually have a high tolerance to frustration (you need that to build effects) but sometimes, i´m ashamed to confess. i loose my patience..

am i the only lunatic here or have this happened to you ?

pd: i rebuilt the darn thing and now it sounds great!

[space_ryerson]

I was recently debugging something and kept getting 0V DC from the circuit. After a lot of frustration, I realized that the plug end of the probe had fallen out of my multimeter.

[dukie]

Outrageous Moments? As far as I can remember, none of my build fire up in the first try and that makes every build outrageous!   

Cheers!