🍏 Apple MacBook Keeps Shutting Down? Here’s What’s Causing It — and How to Fix It

Is your MacBook shutting down randomly, even with battery life remaining or when plugged in? You're not alone — this is a common issue affecting many MacBook users, from college students to busy professionals.

At Gary’s Computer Repair Service, we specialize in Apple repairs and have helped countless Mac users get back to a reliable, stress-free workflow. Let’s break down the why, the fix, and how to know when to get expert help.

⚠️ Common Symptoms of MacBook Shutdown Issues

• 💻 MacBook powers off suddenly without warning

• 🔋 Battery shows 30%+ but still shuts down

• ⚡ Laptop only works when plugged in

• 🔄 Endless restart loops or freezing before shutdown

• 🔥 MacBook gets unusually warm before shutting off

• 🛑 System log shows "Previous shutdown cause: -20, -62, -128" (indicates kernel or hardware error)

🧠 Top Reasons Your MacBook Is Randomly Shutting Down

1. Battery Health Problems

   • Worn or aging battery can’t maintain voltage under load

   • macOS may misreport battery percentage

2. Overheating / Thermal Throttling

   • Clogged fans or dust buildup triggers thermal shutdown

   • Faulty heat sensors or failing thermal paste

3. macOS Software Issues

   • Corrupt OS files, buggy updates, or SMC/PRAM glitches

   • Background processes causing kernel panics

4. Hardware Failure

   • Logic board issues

   • RAM or SSD instability

   • Liquid damage from spills or humidity

5. Charger or Power Supply Faults

   • Faulty charger can cause undervoltage

   • Third-party adapters might trigger safety shutdowns

🔧 5 Fixes You Can Try at Home (Safely)

1. ✅ Reset the SMC (System Management Controller)

This controls power functions on Intel Macs. Instructions vary by model:

• Shut down MacBook

• Hold Shift + Control + Option + Power for 10 seconds

• Release all keys and power on

2. ✅ Run Apple Diagnostics

• Turn off Mac, then power on while holding D

• Check for hardware errors or battery faults

3. ✅ Update or Reinstall macOS

• Run all pending software updates

• Back up your data, then reinstall macOS via Recovery Mode

4. ✅ Check Battery Health

• Go to System Settings > Battery > Battery Health

• If status shows “Service Recommended” or “Replace Now,” your battery may be the cause

5. ✅ Test Without Accessories

• Disconnect all peripherals (USB devices, hubs, external monitors)

• Boot in Safe Mode (hold Shift during startup) and see if issue persists

🛠️ When to Bring It to a Pro

If your MacBook continues shutting down or showing signs of hardware failure, it's time for professional help.

At Gary’s Computer Repair Service, we offer:

• 🔍 Full diagnostics using Apple-grade tools

• 🔋 Battery replacements using genuine or OEM batteries

• 🧹 Fan cleaning and thermal paste reapplication

• 🛠️ Logic board repairs for water or impact damage

• 💾 macOS reinstallation and data recovery

We repair MacBook Air, MacBook Pro, Intel and M1/M2 models, with fast turnaround and nationwide support in Ireland.

📍 Local & Remote MacBook Repairs Across Ireland

We serve customers in Dublin, Cork, Limerick, Galway, and beyond, offering:

• Walk-in or courier drop-off

• Free device check-ups

• Student and business discounts

✅ Final Takeaway

If your MacBook keeps shutting down randomly, don’t panic — the issue could be as simple as a battery replacement or software reset. But if problems persist, expert diagnostics will save you time, stress, and data loss.

📞 Contact Gary’s Computer Repair Service today for fast, friendly Apple support you can trust.