Ksandr
Member
Hi, leaflabs,
I bought your board about month ago.
Yesterday I try to plug in external power supply (12V), I check polarity before, but my board fired and smoked.
What I doing wrong?
Photo:
https://dl.dropbox.com/u/39913355/IMG_0032.JPG
Fired part near "ext" label.
Can you tell me about how I can fix it?
Can you send me sheme of a board, that I can try to fix it.
Sorry for my english.
mikep
Member
Hi Ksandr,
I am not a member of LeafLabs, but the schematic of the Maple R5 board is located here:
https://github.com/leaflabs/maple/blob/master/maple-r5/maple-r5-schematic.pdf
From your posted picture, I assume that the fried part is the diode D2. I am not sure why that would fail though, unless there is something else wrong on the board "downstream".
Can you power the board with a mini-USB cable and does it work doing that? That would mean the 5V regulation circuit has failed.
Here is some more hardware info in the documentation:
http://leaflabs.com/docs/hardware/maple.html
On a related note, since the voltage regulators on the Maple do not have a relatively low rated power dissipation, they cannot supply a lot of additional current. I am not sure if you had any other shields plugged in at the time.
(http://leaflabs.com/docs/hardware/maple.html#maple-power-regulation)
Hope that helps,
Mike
that looks like a 1n148 size diode. Those are only good to about 300 ma in the forward direction which is probably a good thing since the regulators on the maple are good for about that as well. But if you let the smoke out of the diode chances are something is shorted out somewhere else.
mikep
Member
One more thing: in the picture you posted, the jumper is set to USB power and not to EXT.
Based on the schematic there should be no way the diode can be fried that way, unless there is a short on the board itself to ground. Were the jumpers like that when you attached the external power?
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