The Meaning of The Letters on The PCB Circuit Board

Rx is a resistor. There are many resistors in the circuit diagram, arranged in sequence, R1, R2. . .

Cx is a non-polar capacitor, the anti-interference capacitor at the power input end.

IC integrated circuit module.

Ux is IC (Integrated Circuit Component).

Tx is the test point (for factory testing).

Spk1 is Speaker (buzzer, horn).

Qx is a triode.

CEx-electrolytic capacitor, CNx-exhaust capacitance, RNx-exclusion, CONx-connector, Dx-Diode (diode), Lx-inductor/magnetic bead, LEDx-light-emitting diode, Xx-crystal oscillator.

RTH (Thermistor)

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

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

D (diode)

W Zener

K switch

Y crystal

R117: The resistor on the motherboard, the serial number is 17.

T101: Transformer on the motherboard.

SW102: switch

LED101: Light Emitting Diode

LAMP: (indicating) light

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