Reply 20 of 24, by asdf53
asdf53
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Test the gate voltage, please. At least that, and if you have a multimeter with a frequency function, also the gate switching frequency and duty cycle.
When the MOSFET conducts, 5V will briefly appear at the switching node. Normally, the switching controller will try to reduce this voltage by lowering the switching duty cycle. But in this case, you have no load (CPU) connected. The only current that's flowing is a tiny sense current that goes into the switching controller. Because there is almost no current drain, it might not be able to reduce the voltage because the duty cycle for such a tiny current would be extremely low. If this is what's happening, the gate voltage would be 0V and the duty cycle near 0%.
