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Forum Index : Microcontroller and PC projects : Don’t put 13.8v on your MM+....
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
"I think the phrase rhymes with clucking bell." - Blackadder. 
I had just finished my new prototype board, and realised I put the wrong firmware in it, and replugged the 13.8v into what I THOUGHT was the supply, but was actually the line coming from the external opto-coupler. This put 13.8v on the 3v3 input. The PIC32 did not really thank me for that. I knew it was all over when I saw a bright orange spot coming from the IC, but before I could rip out the power, there was a crack sound and a whisp of smoke. ...and we all know that it is the secret smoke that makes things work, and once it escapes, the thing don't work no more...  
*sigh* Smoke makes things work. When the smoke gets out, it stops! |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Deceased PIC32 removed, and footprint clean ready for new chip. 
At this point, I fired the board back up again, and checked all system voltages and other critical areas, just to be sure that this fault did not kill one of the regulators in the process or cause one of them to put out an unhealthy voltage or something, that might cook the new one too - not what anyone wants!  Smoke makes things work. When the smoke gets out, it stops! |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
...and an hour later, we finally are back to the land of the electronically-living. 
It was about the time I expected it to take. Chip-Quik is amazing stuff - I'd be lost without it. Smoke makes things work. When the smoke gets out, it stops! |
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TassyJim Guru  Joined: 07/08/2011 Location: AustraliaPosts: 6283 |
I think I will stick the the more usual slow way of desoldering IC's Glad to see the board is OK. Jim VK7JH MMedit |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Which way is that, Jim? Smoke makes things work. When the smoke gets out, it stops! |
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| mpep Newbie  Joined: 09/11/2014 Location: New ZealandPosts: 29 |
I agree that Chip-Quik is awesome. Highly recommend using it for SMD stuff. |
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CircuitGizmos Guru Joined: 08/09/2011 Location: United StatesPosts: 1427 |
That would be NOT applying 13.8V... Micromites and Maximites! - Beginning Maximite |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
OH!!!!! 
Of course! 
Did not pick up on that! Smoke makes things work. When the smoke gets out, it stops! |
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kiiid Guru Joined: 11/05/2013 Location: United KingdomPosts: 671 |
Out of curiosity, what is the board like in full? http://rittle.org -------------- |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Here you go: 
This is the board I replaced the chip on, and I did it with both the fansink and the EfCom module(white module at top-right) both still in place. Sharp angle on soldering iron, and under the microscope. Smoke makes things work. When the smoke gets out, it stops! |
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| viscomjim Guru Joined: 08/01/2014 Location: United StatesPosts: 925 |
GEEZ GROGSTER... What have you made???? This looks very cool with all those modules! |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Hey there. 
It is a scaled down version of this board on this thread that I made when I was basing everything on a colour Maximite unit. The Micromite Plus has so many new features, I basically decided not to bother rolling out the Maximite-based unit, in favour of a complete redesign to take advantage of the power of the Micromite Plus chip. The GPU fansink is used to cool off three LM350 regulators in cascade arrangement(sometimes called 'Pre-regulator') to provide the three system board voltages of 9v, 5v and 3v3. Current can be a couple of amps surge when powering the network and cell-phone module(the white one) at the same time, and the LCD backlight is quite thirsty too. Smoke makes things work. When the smoke gets out, it stops! |
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| kiiid Guru Joined: 11/05/2013 Location: United KingdomPosts: 671 |
Haha, that's one fat board
http://rittle.org -------------- |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Yeah, she's a bit on the chunky side, but the box is 60mm deep, so it does still fit. It goes into the box I put up photos of in this thread. Smoke makes things work. When the smoke gets out, it stops! |
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| kiiid Guru Joined: 11/05/2013 Location: United KingdomPosts: 671 |
Hey, that was a compliment actually
I meant that is a rich featured board. http://rittle.org -------------- |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Oh....... 
I thought you were just referring to the thickness of it(which did not bother me at all). Smoke makes things work. When the smoke gets out, it stops! |
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