Found on 1 component on 1 board.
What KB4 is
Not identified yet - we know where these parts are, but not their part number. Know what it is, or need one? Ask us.
One code, more than one part. SMD marking codes are short, and manufacturers reuse them: the same code can be a different part in a different package
(a SOT-23 transistor and a SOD-123 diode can both be marked KB4), or from a different maker. Check the package and what the part does in the circuit before replacing it.
Where it's been found
Part number not known yet
Recorded by its marking - the part number isn't known yet
Show on the board