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The root issue is that the chip is not soft-starting again when the input is switched on. Discharging the capacitors triggers the soft-start again. Our supplies have large series resistance due to the wires attached to them and thus the voltage drop caused by the inrush current (even for capacitors that are not fully charged) triggers an Under Voltage Fault, which recovers quickly once the output is switched off.
Possible Solutions:
So yes - we need to drain the capacitors to below 0.7V in order to reactivate soft-start. One solution would be to just turn on a load to drain them quickly (but the controller board will only be able to activate the load for so long, but a better solution would be a discharge resistor on the board. We will need to make sure that the caps can be fully discharged within a given amount of time in order to properly activate the soft start.
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