Hello, the other day while working with an UDOO x86 Advanced Plus, I somehow managed to fry my board. Now my supervisor/professor is requiring me to write a report on how the failure happened and I am seeking assistance in determining possible cause. The UDOO was being powered off of a Viset 36V 10000mAh battery (Link to battery: https://www.amazon.com/HAILONG-36V-...ke+battery+viset+10000mah,aps,70&sr=8-11&th=1) which was being stepped down from 36V to12V by a 36-12V 10A buck converter (Link to buck converter: https://www.amazon.com/SUPERNIGHT-Converter-Electronic-Transformer-Waterproof/dp/B07H23J6WG?th=1). From the 12V output of the buck converter a suitable connector for the 12V DC jack was connected and plugged into the UDOO. The UDOO had been operating normally with this setup for a long time (~2hrs) before the failure happened. After trying to wake the UDOO from sleep mode, my colleagues and I noticed that it seemed to be stuck in sleep mode with the status LED stuck on orange. I tried removing it from its setup (it was on a robot) and shortly after beginning to unscrew it from its mount I noticed a spark near the DC jack plug and then smoke coming from the board. After further investigation, I have observed a burn mark on component D29 (see attached photo) which through further investigation of the schematic I have determined to be an FR014H5JZ "High-Side Reverse Bias / Reverse Polarity Protector With Integrated Over Voltage Transient Suppression" IC (link to datasheet: https://www.onsemi.com/pdf/datasheet/fr014h5jz-d.pdf). On the datasheet for this device it states that the absolute maximum current rating is 8A and it can protect against up to -30V reverse polarity. This component comes directly after the 12V DC jack and this is where I observed the spark/smoke come from. After the failure, the buck converter was checked to determine if it was still functioning correctly and it was not. The buck converter was outputting an incorrect voltage (~1.0-2.0V instead of 12V) when supplied with a 36V input. Therefore, I am left to believe that one of three things happened: (1) While handling the UDOO some connection was bridged on the board which caused a short circuit and an inrush of current that exceeded 10A and caused this component plus the buck converter to fry. (2) Some other component(s) in the UDOO x86 failed which resulted in the stuck in sleep mode condition that occurred just before the spark/smoke and again caused an overcurrent condition which happened to cause D29 and the 10A buck converter to fail. (3) The buck converter itself failed before anything on the UDOO and either caused a reverse polarity greater than 30V (especially being that the battery was a 36V battery) or an overcurrent condition which either way caused D29 to fail. Please let me know if there is any explanation for the hardware failure that I am missing. I have to answer for why the board failed and I frankly don't know. All of my potential causes are pure speculation so any help would be greatly appreciated. Also, a final side question: if D29 is the only component to have failed, if this component were to be replaced, would it be theoretically possible to get this board working again?
