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Topic: [Solved]Pro Mini Exploded!? (Read 913 times) previous topic - next topic

neo_nmik

Apr 05, 2011, 12:57 am Last Edit: Apr 05, 2011, 01:22 pm by neo_nmik Reason: 1
Hi everyone, I hope some one can help...

I'm making a project based on this concept:

http://blog.jpcarrascal.com/2010/03/look-ma-no-wiimote/


Basically, after setting up the transmitter...

(Consisting of a Pro Mini [5v], Xbee + Xbee explorer (Regulated), the insides of a Wii Nunchuck, and a power regulator (solely for powering the nunchuck at 3.3v))

... and having it plugged into a standard ProCell 9v battery on about 5 different occasions, one of the capacitors (That I assume is part of the Pro Mini's power regulation) exploded when I plugged the battery into it...

I tried to whip the battery off, to no avail. The capacitor (labeled c106, and positioned next to the raw and gnd pins) sparked off pretty brightly, and smoked for a couple of seconds... Looking at the capacitor, it's cracked down the centre...

What I really want to know is, was the component faulty, or was it something I did... I've brought another one, but I don't want to replicate the explosion... It's part of my final year Dissertation at university, and I'm quickly running out of time...

Thanks for your time! Hope knows...

Nick

MarkT

Sounds like it was faulty - its the decoupling cap for Vin and 9V isn't unreasonable for Vin - the other possibility is you connected power backwards - which would have damaged more than the cap.

If its just the cap you could use should desolder the remains and either replace it (10uF) or use a decoupling capacitor off the board - depending on how good your surface-mount soldering skills are.
[ I won't respond to messages, use the forum please ]

Grumpy_Mike

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What I really want to know is, was the component faulty, or was it something I did..

Hard to tell but my guess would be something you did. A further guess would be that you are connecting power to the wrong place or the wrong way round.

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having it plugged into a standard ProCell 9v battery on about 5 different occasions, one of the capacitors ..... exploded when I plugged the battery into it

Are you saying nothing had changed between the successful connections and the explosion? On the occasions it did not explode (I can't believe I just wrote that) did it work as expected or was it dead?

neo_nmik


If its just the cap you could use should desolder the remains and either replace it (10uF) or use a decoupling capacitor off the board - depending on how good your surface-mount soldering skills are.


Thats good to know! I'll try that, may need a back-up at some point.


Are you saying nothing had changed between the successful connections and the explosion? On the occasions it did not explode (I can't believe I just wrote that) did it work as expected or was it dead?


I had changed a couple of things, but it was the time before I plugged the battery in for the last time... (If you get me?)



On connecting the battery the wrong way round, I definitely didn't when I plugged it in that time, but I may have caught the pins the wrong way at some other point...

Thanks for your insight guys!

neo_nmik


... did it work as expected or was it dead?


It definitely worked as expected, I'd tested it using the blink sketch, and I used the Xbee's to work the Physical Pixel Sketch on the pro mini.

Thanks again.

Grumpy_Mike

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but I may have caught the pins the wrong way at some other point...

That might have damaged the capacitors causing a short in them. This then would have been enough for it to over heat and explode when it was connected the right way round for a little time.
In over 40 years I have not known a capacitor explode for no reason, it is more likely you damaged it than it was faulty to begin with.

neo_nmik


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but I may have caught the pins the wrong way at some other point...

That might have damaged the capacitors causing a short in them. This then would have been enough for it to over heat and explode when it was connected the right way round for a little time.
In over 40 years I have not known a capacitor explode for no reason, it is more likely you damaged it than it was faulty to begin with.


OK, I'll pay a special attention not to do this...

Thanks for your help.

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