Beagle Blue Boo Boo - Attached the battery the wrong way

My son attached an S2 battery to a Blue yesterday and got a spark. He thinks he had the plug oriented correctly. He re plugged it in again and attached the Blue to a 12V supply. The Blue fired up and the battery charged. Once charged we removed the 12V and the Blue died. The Blue reboots when the 12V supply is restored, but won’t run on the battery alone. It looks like we melted part of the regulator. Notice the 8 pin device in the top center of the picture.

I’m assuming the part can be replaced. Does anyone know what part it is?

–Mark

Q1 is the MOSFET-N between the LIBO’s BATT_MINUS and GND

https://github.com/beagleboard/beaglebone-blue/blob/master/BeagleBone_Blue_sch.pdf

https://www.digikey.com/products/en?lang=en&site=us&KeyWords=SI4778DY-T1-GE3

https://github.com/beagleboard/beaglebone-blue/blob/master/BeagleBone_Blue_BOM.csv

Regards,

My son attached an S2 battery to a Blue yesterday and got a spark. He thinks he had the plug oriented correctly. He re plugged it in again and attached the Blue to a 12V supply. The Blue fired up and the battery charged. Once charged we removed the 12V and the Blue died. The Blue reboots when the 12V supply is restored, but won’t run on the battery alone. It looks like we melted part of the regulator. Notice the 8 pin device in the top center of the picture.

I’m assuming the part can be replaced. Does anyone know what part it is?

I believe the silkscreen next to it says PROT, which would make it the S-8261.

I think this is the 3rd occurrence I’ve heard about. Though yours is the first to identify what might have blown. Guess the keyed connector isn’t keyed enough. I will add warnings to the wiki.

Thanks Robert. I should have zoomed in.

I’ve added it to My Favorites at Digi Key. I need a few more things to order so the cost is greater than the postage.

–Mark

Further to my previous post bought the MOSFET from digikey, installed it today and it now works fine. I’m pretty certain in my case though that I didn’t connect the battery the wrong way round. Anyway, thanks to this group it’s now back working again.
Here’s the new installed component

2019-07-31-202742.jpg