On Fri, Mar 28, 2025 at 11:00 AM, Austin K4HYD wrote:
It's still unclear why the MOSFET would blow in this case as it's rated for 20V
The MOSFET would blow from over-current, not over-voltage.? And high current will happen if +5V is somewhere shorted to ground, or Q108 is turned on all the time, which causes zener D108, which is trying to keep the voltage down to 5.6V to conduct very strongly and perhaps fuse shorted in doing so.? A 12V short to the 5V bus would also cause a lot of current to go through Q108, at least until D106 fails shorted.
