Moments of stupidity...

[Silver Blues]

Wanna hear something funny? I finished building a 5-knob Engineer's Thumb on Sunday. When I fired it up, I got signal, but it wasn't really doing anything... and it was sitting just below unity volume at maximum rotation of the Level control. Bright switch does nothing. Popping on bypass. The Threshold was cutting off my signal at both extremes, and if I set it right at the line before cutoff at the top end, it would overdrive if I played hard.

I probed it endlessly. Twice. The first time I found the 3080 not pushed in all the way. No big deal, everything else fine. Tried again, a little more level but nothing different.The second time I tested all the pots and went over the board layout. I was like... but why? the board is FINE, all voltages check out, the pot wiring is FINE, the pots are FINE, all the offboards are in the right place, the true bypass wiring is FINE (except modified a little from the diagram I used for ease)...

Probed it a third time... brushed a capacitor and it beeped for continuity.



Yeah... turns out what I thought was a 100pF cap is actually a 100uH inductor.

The damn thing was a little blue sphere marked 101K. To me, that was a capacitor.

Hopefully replacing it will fix the problem.

Anyone else care to share any funny moments of stupidity?

[IvIark]

I tried to fault find an IC build once, can't remember which one, maybe a Honey Bee, and was trying to work out what was wrong for ages.  Cuts fine, links fine, components placed fine, component values fine.  Ended up throwing it against a wall.  

Then I looked on my worktop and saw the IC I hadn't put in the socket yet.

[GoranP]

I don't have nearly enough builds to have accumulated spectacular d'oh! moments...

My build faults were mostly component failures and some wrong values so nothing out of the ordinary to report...

I guess my worst moment so far happened a month or so ago, it was way past midnight on a worknight and I'm waiting for my solder iron to get hot... it's a simple 220v job that I picked up at a hardware store for next to nothing. So I'm waiting and waiting, holding some solder to it and cursing the blasted thing for not melting it when all I have to do is solder a few pots and test to see if it works before going to bed. This went on for at least 10 minutes when it finally dawned on me that the iron would most likely work a whole lot better if I actually plugged it in...

[Vince]

Only recently I made a greenringer. Built it all up. Tested, very slight sound. probed. swapped all the caps/transistors etc... nothing. Built another, same results, by this time I was near in tears.. just about to slam it in the bin with the first attempt then noticed I had a transistor in the wrong socket!

[Dave]

When hooking up circuits to my test rig I'm endlessly getting input and output wrong way round. I think the best one was when I had a board hooked up, worked in bypass and nothing when engaged, spent the usual 20 mins of cursing and swearing before it dawned on me that the power supply was sitting idly on the floor.......
Thanks
Dave

[PStevenson]

I've never had a moment of stupidity regarding electronics cause I've been doing it for so long and I'm just too meticulous when I build stuff.
however I had reflex stupidity once where the soldering iron somehow slipped out of my hand and without thinking I grabbed it by the tip as it fell

that was the second most painful thing in the world - the first being standing on a plug with bare feet

[adstrum]

Had a similar experience to Goran. I was holding a piece of solder up against the soldering iron tip and getting frustrated that it wouldn't melt. Eventually realised that I was holding a piece of bare hookup wire. Now I never use loose pieces of solder. I always run it directly from the reel.

[Torpy10]

I've been making stompboxes for a couple of years now and I've made a vero test rig to test the circuits before putting them in a box.
One time I tested a vero and it all worked well and then I put it in a box and wired it up and it was really quiet ? After 3 hrs looking for the problem - pulling it apart , checking components, wiring etc,   ....why did it work before I boxed it but not now ?
I had the in and out guitar leads back to front !
What a dork.