Drone Engineer Trainee — HYPSTUMA
Diagnosed a complete electrical failure on a 450 mm quadcopter to reverse polarity through three sequential elimination checks, identifying burnt MOSFETs from absent reverse current protection.
A 450 mm quadcopter came in completely electrically dead. The interesting part of a fault like that is not the fix — it is not jumping to a conclusion before the evidence supports one.
I worked through three sequential checks, each one eliminating a layer: the battery via multimeter, the PCB via USB-C, and then MOSFET continuity. That last check found burnt MOSFETs, and the root cause behind them was reverse polarity on a board with no reverse current protection designed in.
So the real failure was not the MOSFETs. It was a design that allowed a reversible connection to destroy the board — the components that burnt were doing exactly what unprotected components do.
I combined structured fault elimination with expert consultation rather than guessing at replacements, which is what kept the diagnosis pointed at the cause instead of the symptom.