Sends and receives the phone's radio signal — cellular, Wi-Fi, Bluetooth and GPS each have their own compact antenna. A fault here means poor or no network.

Routes the signal path between the different antennas and the transceiver depending on which network band or service is active.

Voltage-Controlled Oscillator — generates the exact frequency the CPU requests for calls and data. If faulty, calls fail or the network drops entirely.

Filters the incoming signal frequency so incoming calls and data come through clean. A faulty RX filter causes incoming call or network trouble.

Filters the outgoing signal frequency during calls and data transmission. Faults here affect outgoing calls specifically.

Power amplifier and band-pass filter near the antenna switch — boosts and cleans the network signal. A short here can cause a dead phone or very weak signal.

Manages baseband signalling and coordinates the radio components with the CPU to keep the phone connected to the network.

A precision timing crystal that sets the reference frequency for outgoing calls. A faulty crystal causes network and call-quality issues.

Controls and regulates current to the whole phone during charging. When faulty: phone won't charge, charges intermittently, or heats up while plugged in.

The main processor — controls every function of the phone. If it fails, the phone can go completely dead, with no display and an unresponsive keypad.

Distributes regulated voltage from the battery to every other IC on the board — the phone's internal power supply.

Real-Time Clock — keeps time and date running even when the phone is powered off, using a small backup supply.

A key resistor located near the charging IC in the power section, often checked first during charging-fault diagnosis.

Processes audio signals for the speaker, earpiece and microphone — handles call audio, media playback and recording.

Manages the phone's user-interface logic — keypad, buttons and basic input handling before it reaches the CPU.

Drives the phone's buzzer or vibration motor for alerts, notifications and ringtones.

Connects the microphone to the audio IC — carries your voice during calls and voice recordings.

Instant-access memory for multitasking — every open app or game runs from here. Low or faulty RAM causes lag and slow performance.

Also called EEPROM/ROM IC — stores the phone's software. A faulty flash IC often means the phone won't boot or run properly.

Stores the operating system and pre-installed apps that can't be removed. Problems here usually show up as software faults.

The main printed circuit board for smartphones. Acts as the central hub connecting the processor, memory, network components, and power supply.

Main processing board for LED & LCD TVs. Controls power distribution, audio/video output, HDMI ports, backlight circuitry, and smart TV functions.

Universal motherboards and main circuit boards available for all types of electronic devices, tablets, laptops, and custom electronic gadgets.