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5 V rail can't be 5 V #22

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@dead-lock-ed

There are reports of 5 V fan and accessory rail (+5V net) outputting around 4,7 V.
This issue can be tracked back to the PCB, where the output of buck converter K7805-2003 (PS3 on schematic) isn't fed directly to the 5 V rail, instead it has to go through a BAT60A (D20) diode.
At room temperature it exhibits around 0,3 V forward voltage at rated output current of the regulator, which can explain the lower than optimal output voltage.
This is too low voltage for many 5 V devices to operate, which greatly reduces the usability of the mainboard.
I attach a screenshot of the schematic showcasing the problematic region image-73.png

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