Help required to identify circuit board

[jaksonlee]

Resistors are often marked with an “R” to help identify them on the circuit board. A potentiometer is a variable resistor and will often have a “VR” to indicate it on a circuit board. Their value is typically marked on them, and they may have a three-digit code or letter code.

 

[bertus]

Hello,

More reference designators can be found on this page of the wiki:
https://en.wikipedia.org/wiki/Reference_designator

Bertus