How many things can go wrong in one build?

[trjones1]

I haven't been building many pedals lately, but when I used to I prided myself in getting most of them to work the first time they were fired up.  I made a Rat recently that I needed for a band I'm in.  Turned it on and it was dead, so I started the debug process.  Would you believe that I eventually got it working after finding:

1. Dead IC
2. A bridged vero trace
3. I forgot to install the jfet altogether
4. Terminals on the tone knob were bridged
5. Output jack wired to input spot on switch and vice versa
6. Dead LED (not sure why)
7. Miswired replacement LED

I guess the one positive I take out of it is that my trouble shooting skills are still strong.

[commathe]

I would have given up way before that knowing me... 

[R.G.]

Scars are the visible reminders of the most vivid parts of our educations.

You're now a LOT more equipped to deal with these problems in the future. And congratulations on being persistent enough to fight through them. Good work!

[bool]

Exactly 63,15 things can go wrong in one build.

[italianguy63]

What I hate is when you fix a problem, and it breaks two more.  i.e. you unsolder a component, and it breaks a wire, or lifts a trace, etc..  And, it becomes a domino chain of things to fix.

MC

[diydave]

What I hate is when you fix a problem, and it breaks two more.  i.e. you unsolder a component, and it breaks a wire, or lifts a trace, etc..  And, it becomes a domino chain of things to fix.

MC

Or when you migrate it to your hammond-enclosure and the thing goes dead for no apparent reason.

[MrStab]

even after a year & a half of doing this, i make a total arse of myself on this forum because one problem leads to another or leads to forgetting to do obvious stuff etc.. then i get frustrated and the task seems even more insurmountable.

it happens, i guess. and you've totally hit the nail on the head, IMO: troubleshooting experience points! there's always something to be redeemed when you're being creative.

[R.G.]

Remember the old cliche: debugging is like peeling onions - you remove one layer, and it reveals another layer to be removed, and frequently there are tears.   

Expect it - and revel in it. As Thomas Edison said of his phonograph, "I was always afraid of things that worked the first time."

[Mark Hammer]

If you build on perf, you can probably multiply the things that can go wrong by 2x.  The constant flipping over, back and firth, leads to losing track of what went where and what's connected to what.  Just one of the reasons why I like to use multiple colours of wire, and adopt a personal "wiring code" (white is always in, blue is always out, purple is always feedback, treble is always yellow, mids orange, and bass brown, speed is grey, etc.)...so I can keep track of things.

There are two aspects to "the learning".  One is, as you quite correctly note, learning what to check for in the troubleshooting.  The other is learning what steps to take, proactively, so that some things can be safely removed from the troubleshooting checklist.

[Perrow]

Exactly 63,15 things can go wrong in one build.

I find it funny that that comment comes from someone with the username "bool" 

Expect it - and revel in it. As Thomas Edison said of his phonograph, "I was always afraid of things that worked the first time."

Wasn't it Edison that said he didn't make mistakes, he just ruled out possibilities. Wait, found the quote and it's close to what I said; "I have not failed. I've just found 10,000 ways that won't work." There's another Edison quote that goes well with debugging; "When you have exhausted all possibilities, remember this - you haven't."

He even foresaw breadboarding; "To invent, you need a good imagination and a pile of junk."

[Digital Larry]

I'm amazed at the number of pedal builders who (apparently) don't use a voltmeter or scope for debugging.  I can understand not buying a scope (I suppose, though I wouldn't want to start doing any electronic designs without one), but a voltmeter? 

These discussions do remind me why I started getting into software more than building more gadgets as the years went on.  Once I saw a high speed surface mount pick and place machine with optical inspection in action, I concluded that electronics assembly is not really a job suited for human beings.  That is just my biased point of view for today and believe me I do respect all of the work and learning you are doing.

[bukas]

( number of parts)^3

and just in case +1

[amptramp]

To add to the list, I have one unit powered by ±12 volts and I used a 4-pin power plug (keeping one pin in reserve in case I needed a chassis ground pin) and got all connections wrong.

[karbomusic]

I'm amazed at the number of pedal builders who (apparently) don't use a voltmeter or scope for debugging.  I can understand not buying a scope (I suppose, though I wouldn't want to start doing any electronic designs without one), but a voltmeter?  

Not me, I use all of the above when building and debugging but I do much less debugging because of it. Started out that way when I first tooled up. I'm replying because now that I know how to use most of the stuff, I can attest that it plays a very large role in my not having to troubleshoot near as much post build and saves me hours and hours of time in the long run and across the board. I don't use the tools to try to see how it sounds, I use them to confirm and ensure the individual parts and circuit are working properly before hearing it which greatly increases the chances of it sounding right provided it isn't a bad design.

It is really, really, really nice to build a circuit, box it and start using it immediately.

[Strategy]

One of my DIY mentors said "go slow" at the beginning of my DIY hobby, and I didn't listen closely enough. A year or so in after many failures I slowed WAYYY down (like sometimes I'll poke at a project casually for months or even years) and the amount of trouble shooting I have to do is greatly reduced. "Check twice" before soldering. And if I hit something in the build doc or schematic that I can't comprehend...I just stop until I understand it. (and often run to the forum heheh).

Mark mentioned personal wiring codes, I've even developed a kind of pre trouble shooting QA/QC check, where I'll do little checklist / reminder type routines - part directionality, trace back over the wiring, etc. The number of errors I catch from doing this always shocks me, what am I doing, populating boards half asleep???

Lesson learned, go slow!!

Strategy

[Seven64]

i forgot 2/5 caps on my last vero build.

it was an optical compressor for bass.

i spent 5 hours building makeshift vacrols with different color and sized LED's before noticing.

[Clips]

That moment when you finally figure out what was wrong, though, and all the pieces fall into place and everything starts working perfectly.. best feeling in the world.

[deadastronaut]

its usually the bleedin obvious that gets me.....like forgetting to put the chip in the socket...(that's what being too careful does to ya! )

[trjones1]

its usually the bleedin obvious that gets me.....like forgetting to put the chip in the socket...(that's what being too careful does to ya! )

The real forehead-slapper for me was mixing up the input and output jack wires.  It always looked a little weird to me, but I never thought I'd be dumb enough to make such a simple mistake.

[bluebunny]

like forgetting to put the chip in the socket...

Ha ha!  Been there, done that, and even posted the gut shots!   

At the weekend, I was several solder joints into a perf build before I spotted that my very first reference piece (an IC socket - what else??) was in the wrong place.  Much de-soldering and pad-lifting (and swearing) ensued...