What Is a Logic Board? (And Why It’s the Heart of Your Phone)

If your phone were a person, the logic board would be the brain — quietly running everything in the background.

You’ll never see it in daily use, but without it, your screen wouldn’t light up, your apps wouldn’t open, and your battery wouldn’t charge.

So, What Exactly Is a Logic Board?

A logic board (also known as a motherboard or mainboard) is the central circuit board inside your phone.

It connects and controls every major component — screen, camera, battery, speaker, buttons, and charging port — through thousands of tiny circuits.

It’s made up of layers of copper tracks, microchips, and processors that handle everything from graphics to power delivery.

What Happens When It’s Damaged?

Logic board damage can cause a wide range of mysterious symptoms:

• No power or random shutdowns

• No display or touch response

• No sound, Wi-Fi, or charging

• Face ID or camera not working

These faults often appear after liquid damage, drops, or electrical surges.

While screen or battery replacements are straightforward, logic board repairs are precision work — involving micro-soldering under a microscope.

Can It Be Repaired?

In many cases, yes — especially if it’s caused by a faulty component like a charging IC or power chip.

At Phone Repair NZ, we can diagnose board-level faults, determine whether repair or replacement is viable, and recover your data whenever possible.

When to Suspect a Logic Board Issue

If your phone doesn’t respond at all — even with a known-good screen or battery — the issue might lie deeper.

Bring it in, and we’ll run a diagnostic test to isolate the fault before you spend money on unnecessary parts.