2 days of work, gone!!

Thread Starter

CVMichael

Joined Aug 3, 2007
419
I spent 2 full days (morning till night), last weekend, to make a PCB board for the motors drivers for my robot. 4 DC motors and 1 stepper motor connected to a PIC32 microcontroller.
I was working on my robot yesterday, and I was connecting the battery jacks to the PCB board. The batteries are in parallel, in total of 12V 16 Amps, I connected the negative, and plugged the jack in the PCB, then I took the positive wire (to connect it to the jack), and it slipped through my fingers, and it touched the PCB board on a trace where the negative was.
It melted the traces of the PCB, and then the PIC32 chip popped, and burned, and who knows what else is burned (probably everything)...

I know all the mistakes I made, you don't have to tell me...

I am so sad :( I just had to let it out...
 

BMorse

Joined Sep 26, 2009
2,675
Live and learn. It has to happen to each one of us once in our lifetimes.

Once?!? I must be taking more of my fair shares then :)

Did that once with my Pic32 starter kit, was testing interrupts when I touched my "interrupt" trigger wire (which was connected directly to ground) and accidentally touched the +V rail and "pooof!", board was dead...
 

BMorse

Joined Sep 26, 2009
2,675
if it makes you feel any better, you can watch me fry my Pic32 starter kit here>> http://youtu.be/32j9wORr2_k it is around 0:41 secs into the video.... :) But I did manage to salvage the board by replacing the protection diode they had on the board, maybe you should add something like that to your next PCB...
 

Thread Starter

CVMichael

Joined Aug 3, 2007
419
I'm at work now, so I can't (should not) watch videos...

What "protection diode" are you talking about? Is it a regular diode? or a special diode for this purpose?
 

ErnieM

Joined Apr 24, 2011
8,377
One day at work (happened to be a Saturday doing unpaid overtime to meet a critical shipment date) I slipped a scope ground probe and instantly took out about $30K in test equipment: power shorted thru the IEEE-488 bus and took out the computer, a DVM, spectrum analyzer, electronic load, everything but the power supply itself.

When my boss asked me about this Monday morning I told him the equipment was now in the calibration department for repair, I had borrowed other equipment from engineering, revamped the test program for semi-manual operation, and the parts would be on the shipping dock by lunch (on schedule).

All he said in reply was "OK" and left me to my testing.

Doo-doo happens. It's how you respond that counts.
 

loosewire

Joined Apr 25, 2008
1,686
Two days tells the story ,too much stuff in two days.You need to take it slow and

steady. Look at some of the boards posted in albums,look and see how many was

done in two days.
 

Thread Starter

CVMichael

Joined Aug 3, 2007
419
The problem was that I short circuited the positive on the ground through the PCB board.

The traces on the back side melted in like 6 places, and then current flowed through the components. There was a huge spark when the wire touched the PCB, and the PIC32 had a small flame in the center.

The batteries are 16 Amps, so it's no surprise that everything melted :D
 

Thread Starter

CVMichael

Joined Aug 3, 2007
419
By the way... is there some kind of insulator like a paint, that I can just brush on top of the PCB and components?

Theoretically it should be something like this, right?
 
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