The Meaning Of Those Letters On The PCB Board

Rx is a resistor. There are many resistors in the circuit diagram, which are listed by serial number, R1, R2. . .

Cx is a non-polar capacitor, anti-interference capacitor at the input of the power supply

IC integrated circuit module

Ux is an IC (Integrated Circuit Component)

Tx is the test point (for factory testing)

Spk1 is Speaker (buzzer, speaker)

Qx is a triode

CEx-electrolytic capacitor, CNx-discharge, RNx-exclusion, CONx-connector, Dx-Diode (diode), Lx-inductor/bead, LEDx-LED, Xx-crystal.

RTH (Thermistor)

CY (Y capacitor: high voltage ceramic capacitor, safety)

CX (X capacitor: high voltage film capacitor, safety)

D (diode)

W regulator

K switch class

Y crystal oscillator

R117: The resistance on the main board, serial number 17.

T101: Transformer on the main board.

SW102: switch

LED101: LED

LAMP: (indicator) light

Q104 (E, B, C): Transistor, E: Emitter, B: Base, C: Collector