Hardware issues
Although usual intention of the original hardware designer is to produce high quality electronics, this cannot always be guaranteed by vendors re-using open-hardware design or altering it in any way.
The purpose of this page is to facilitate board inspection to detect deviations from the original design, which may deliver sub-optimal performance.
Typical causes of failures
Chip with less memory or lower clock different from original STM32 F405
Prototype chip (ARM A) with bugs instead of latter silicon revisions (ARM Z, 1, 2, Y)
Shorts or not enough solder paste
Bad capacitors causing resets when connecting board over USB
Bad regulators
Missing ESD protection diodes on Flexi, Flexi-io or Main port (except Nano which has none by design).