The meaning of those letters on the PCB
Rx:the resistance, a lot of resistance in the circuit diagram, according to theserial number, R1, R2...
Cx:a non-polar capacitor, power input capacitance interference
IC:integrated circuit module
Ux:an IC (Integrated Circuit Component)
Tx:the test point (factory test)
Spk1:Speaker (buzzer, speaker)
CY(Y capacitor: high-voltage ceramic capacitors, safety regulations)
CX(X capacitor: high-voltage film capacitors, safety regulations)
R117:Motherboard resistance, number 17.
T101:Transformer on the motherboard.
Q104(E, B, C): Transistor, E: Emitter, B: Base, C: Collector