Dumbest 'electronic' mistake you ever made

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

I was hot wiring my Camaro when I was 18 or so. I would take a wire and from the fuse box, find a 12v source and run it to the accessory fuse. This would keep the car running after I took another wire and went from a 12v source to the starter. I can't remember if there was a fuse for the starter and I could simply use the fuse box trick to get it to turn over or if I had to crawl under the car. Anyway, one night I went to hot wire it and some how I managed to ground that 12v source. The wire pretty much evaporated. It left this indent in my thumb where it was. The indent was nice and white. I could lay a piece of wire the same size right in the indent. It hurt soooooo bad! After that, I just decided to replace the ignition switch!

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

Putting a wet electrolytic cap the wrong way will cause electrolysis that will boil off the liquid in it. This will cause the cap to possibly explode from pressure. The pressure can also push the electrodes together causing a short, which will tend to destroy fuses not to mention boiling off even more liquid...

I don't know about polarized solid polymers, but the dielectric failure and causing solids to meltdown and subsequent short-caused rapid heating explosion quite possibly still applies.

Thanks. So when you say a wet electrolytic cap, does that just mean all electrolytic caps? I knew they were polarized but I just thought they wouldn't work. This is great knowledge. I'll make sure I'm extra careful in the future!

[eccerr0r]

Re: Dumbest 'electronic' mistake you ever made

Putting a wet electrolytic cap the wrong way will cause electrolysis that will boil off the liquid in it. This will cause the cap to possibly explode from pressure. The pressure can also push the electrodes together causing a short, which will tend to destroy fuses not to mention boiling off even more liquid...

I don't know about polarized solid polymers, but the dielectric failure and causing solids to meltdown and subsequent short-caused rapid heating explosion quite possibly still applies.

[goontron]

Re: Dumbest 'electronic' mistake you ever made

Wrench across a 24v truck battery... There is now a white mark across my hand and fingers....

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

When you put an electrolytic cap in the wrong way, doesn't it just not work? I don't think I've ever heard of them shorting something or blowing fuses. Am I mistaken on this?

[TechGeek]

Re: Dumbest 'electronic' mistake you ever made

Did any of the caps go "POP!!!"?

[mikay786]

Re: Dumbest 'electronic' mistake you ever made

I've only been tinkering roughly a year but today I think I managed to goof up good.

Just finished a recap, ended up some how putting the main filter caps in wrong way round. Well one right way and the other wrong. Even had pictures of the board on my screen and they were clearly marked on the board. Only explanation is was fitting them upside down with one hand holding the cap in place.

Thankfully only blew the internal 10a fuses rather than anything else, oddly enough didn't blow the external 2.5a fuse.

[ben7]

Re: Dumbest 'electronic' mistake you ever made

But by far my worst ever mistake was about 20 years ago. A friend had just acquired an old VW Beetle and "it wouldn't start". So, to save me time, he brought the starter motor round to mine to test it. Well, as it happened, I had a nice big Transit battery on charge, so I thought 'Easy, I'll just pop the starter across the terminals'. Anyone guess what happened next?
Well the resulting BOOM (the spark ignited the H2 & O2 that the battery was giving off as it was fully charged) not only destroyed a perfectly good battery, it also had numerous neighbours out thinking someone in the street had been shot (or worse) and had me in the Edinburgh Eye Hospital for the next 4 days. Also had to cancel a holiday to Florida.

Yikes! LOL!

Well the resulting BOOM (the spark ignited the H2 & O2 that the battery was giving off as it was fully charged) not only destroyed a perfectly good battery, it also had numerous neighbours out thinking someone in the street had been shot (or worse) and had me in the Edinburgh Eye Hospital for the next 4 days. Also had to cancel a holiday to Florida.
Happily I lived to tell the tale, and no lasting damage (to me). The battery was a write-off, and the Beetle was never mentioned again.....

[Trevtron]

Re: Dumbest 'electronic' mistake you ever made

OMG, loving these- I've done quite a few of them myself, one frustrating incident was when the legend on the PCB was wrong, that 470μF didn't last long- trouble is my workshop is in the basement, and nasty smells permeate upwards through the rest of the house if I don't close the door in time- with the resultant complaints from the OH.
But by far my worst ever mistake was about 20 years ago. A friend had just acquired an old VW Beetle and "it wouldn't start". So, to save me time, he brought the starter motor round to mine to test it. Well, as it happened, I had a nice big Transit battery on charge, so I thought 'Easy, I'll just pop the starter across the terminals'. Anyone guess what happened next?
Well the resulting BOOM (the spark ignited the H2 & O2 that the battery was giving off as it was fully charged) not only destroyed a perfectly good battery, it also had numerous neighbours out thinking someone in the street had been shot (or worse) and had me in the Edinburgh Eye Hospital for the next 4 days. Also had to cancel a holiday to Florida.
Happily I lived to tell the tale, and no lasting damage (to me). The battery was a write-off, and the Beetle was never mentioned again.....

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

I'm pretty darn sure I didn't do stuff this bad when I was younger xD

Well, only once did I stick a screwdriver in something without knowing what I was doing ... when I was a toddler. Now I have a scar to prove my love/obsession of electrical engineering xD

I wasn't quite a toddler. Maybe 6 or 7. I know the guy we bought it from said something about it wouldn't run Windows 2. I had no idea what Windows was. I was around 6 years old, maybe 7 or 8. I used to rip everything apart when I was younger. With the PC, I saw those little slots and thought oh boy! Something goes in there! Lets try a screw driver!

[ben7]

Re: Dumbest 'electronic' mistake you ever made

I had an old 286 computer and when it was running, I stuck a flat head screw driver into one of the expansion ports. It displayed some weird messages on the monitor, being a little kid, I thought I was hacking the PC. I remove the screwdriver and insert it into another slot and next thing I know, a big spark and the whole PC just shuts down. It didn't work after that. Or atleast I don't think it did. I was soooo afraid to tell my parents. They just bought it for me (for around 100$). Later on, when I got to know a bit more about PCs, turns out the monitor that I had hooked up went dead (I'm assuming that night). So I guess there's a chance the PC still worked and it was just the monitor that I some how fried.

I'm pretty darn sure I didn't do stuff this bad when I was younger xD

Well, only once did I stick a screwdriver in something without knowing what I was doing ... when I was a toddler. Now I have a scar to prove my love/obsession of electrical engineering xD

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

Yeah It was mistakes like that though that really made me want to learn how everything worked I guess. So in a way, I guess it helped me become who I am today.

[ben7]

Re: Dumbest 'electronic' mistake you ever made

That was pretty stupid.

Uh, make that very stupid xD

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

I had an old 286 computer and when it was running, I stuck a flat head screw driver into one of the expansion ports. It displayed some weird messages on the monitor, being a little kid, I thought I was hacking the PC. I remove the screwdriver and insert it into another slot and next thing I know, a big spark and the whole PC just shuts down. It didn't work after that. Or atleast I don't think it did. I was soooo afraid to tell my parents. They just bought it for me (for around 100$). Later on, when I got to know a bit more about PCs, turns out the monitor that I had hooked up went dead (I'm assuming that night). So I guess there's a chance the PC still worked and it was just the monitor that I some how fried.

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

When I was really young, I went to Toys R US and saw that they had a gameboy hooked up to a TV screen through an NES. I didn't realize they had a cart that the gameboy game plugged into. I went home, cracked open the NES and gameboy and grabbed a jumper wire. I started touching it to places on the gameboy with one hand and to another place on the NES thinking if I found the magical place, I'd see the gameboy screen on the TV! All of a sudden, a nice spark and the wire starts getting real hot. I ruined the NES and the gameboy. That was pretty stupid.

[Spork Schivago]

Re: Dumbest 'electronic' mistake you ever made

We were in high school, my friend Matt and I. Just learning about computers (even though, back then, we thought we knew everything! How wrong were we?). Anyway, I ordered a motherboard and a CPU. I was building my first PC from scratch and wanted his help (he knew more than I did at the time). We get it all together and it wouldn't POST. So we take the CPU (a 5x86 Cyrix I think) and started turning it 90 degrees and plopping it back in and trying again! Still nothing. Matt notices a little 2 pin header on the motherboard that doesn't have a jumper and then we notice a little two pin female cord coming from the power supply. Being the geniuses that we were, we figured that cord must plug into the motherboard. We plug it in, turn it on again and nothing...at first. Then all of a sudden Matt asks if I smell smoke. We look down, the motherboard is smoking. Turns out that little wire was to power a small numerical display on the front of the case that shows how fast the CPU is running.

Back then, motherboards didn't cost nearly what they cost today. I contacted the company and neglected to tell them what we did. I just said it wouldn't post. They were nice enough to let me RMA it and get another one.

[ben7]

Re: Dumbest 'electronic' mistake you ever made

Ooooops.... ever lost B-phase power at home?

It's highly unlikely that he has 3 phase power unless he lives in an apartment building. (even then, some only have single phase power)

Nope

Unless this was supposed to be some sort of joke that I didn't get. :P

[Pentium4]

Re: Dumbest 'electronic' mistake you ever made

Nope

[TechGeek]

Re: Dumbest 'electronic' mistake you ever made

About 2 and a half years ago, I recapped an Allied PSU, one of those with the "clam shell" style casing. I was so excited to test it that I forgot to put the plastic cover under the solder side. Flipped the power switch, ka-BOOM!

Ooooops.... ever lost B-phase power at home?

[Pentium4]

Re: Dumbest 'electronic' mistake you ever made

About 2 and a half years ago, I recapped an Allied PSU, one of those with the "clam shell" style casing. I was so excited to test it that I forgot to put the plastic cover under the solder side. Flipped the power switch, ka-BOOM!