Found on 2 components on 2 boards, in SOT23 package.
What 1D is
- MMBTA42 (SOT23 ยท on 1 of the parts below)
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 1D), 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