What Is the Motherboard?

The motherboard (called the logic board in iPhones) is the main circuit board inside your device. It controls everything: charging, touch, audio, camera, signal — all of it. When it fails, your phone either becomes unstable or stops working entirely.

Unlike a cracked screen or bad battery, this isn’t a plug-and-play fix. Motherboard repairs require micro-soldering under a microscope and component-level diagnostics.

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How to Know if It’s a Motherboard Problem

Not every dead phone has a logic board issue — but here are common symptoms we see at YKL that usually point to it:

⚫ Phone is Completely Dead

No charging, no sound, no vibration, no light — despite changing the battery or screen.

🔁 Boot Loop or Freezing on Logo

If it keeps restarting or gets stuck on the Apple/Samsung logo, the storage chip (NAND/eMMC) may be failing.

🔋 No Charging or Fast Battery Drain

You’ve changed the battery and charging port — but it still won’t charge properly? Likely a charging IC fault (like Tristar or Hydra in iPhones).

📱 Black Screen, But Phone Is On

If your phone vibrates or rings but the display stays off, this may be a backlight circuit or display power fault — often board-level.

🎙️ No Sound or No Mic

On certain iPhones, like the iPhone 7 or 6 series, this is often an audio IC issue after drop damage.

💧 Water Damage

Even if your phone seemed fine after a splash, corrosion inside the board can appear later and cause unexpected failures.

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What Causes Logic Board Damage?

• Water or liquid exposure

• Drops or impact damage

• Using cheap/third-party chargers

• Heat and age-related wear

• Poor repair attempts by untrained technicians

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What Should You Do? (And Not Do)

✅ DO:

• Bring it in for diagnostic testing at YKL. We don’t guess, we test.

• Tell us if the phone gets warm in one spot. That often helps locate shorts.

• Back up your data regularly, if your phone is still working.

❌ DON’T:

• Keep charging a water-damaged phone — it can worsen internal damage.

• Rely on software fixes or “online tricks” for hardware faults.

• Try DIY board repair — it almost always makes the issue worse.

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Is It Worth Repairing?

We’re honest with our customers: not all board repairs make financial sense. But here’s when they do:

• You need to recover important data (photos, videos, documents, etc.)

• Your phone is a recent model (e.g., iPhone 13/14, Galaxy S21+)

• Replacement costs more than repair — and you want to keep the device

 

Come to YKL for expert motherboard repair

• 🔧 Power IC replacement

• 🔧 Short circuit tracing and repair

• 🔧 Charging IC repair 

• 🔧 Backlight and audio circuit repair

• 🔧 Component-level micro-soldering under microscope