MacBook won't charge — is it the charger, cable or battery?

A MacBook that refuses to charge sends most people straight to Apple for a £500+ battery replacement. Before you do that, work through these four checks — the first three cost nothing, and one of them is usually the answer.

Quick diagnosis from the menu bar

Click the battery icon in the menu bar. What does it say?

• "Not Charging" (but charger connected) — SMC / power-management issue, or battery is at 100% and system is being clever about charge cycles. See section 3.
• "Charger connected, Not charging" constantly — hardware fault, work through sections 1-4.
• No response at all, laptop off — total power path failure. Section 1 first.
• "Service Recommended" / "Replace Soon" — battery health is below 80% and the cells are worn. Section 4.

Also: System Settings → Battery → Battery Health → Info shows cycle count and maximum capacity. Anything under 80% capacity is a worn battery.

1. The charger

Apple chargers fail a lot more than people realise, especially MagSafe cables from 2016-2019 era and USB-C chargers exposed to heat.

• Try a different Apple-branded charger if you can borrow one.
• Third-party chargers that are NOT MFI-certified can fail to deliver enough power — many "works with MacBook Pro" cheap USB-C chargers are 60W when the Pro needs 87W or 96W. Use the Apple original where possible.
• Check the cable for visible damage — bulging, tears, exposed shield near the plug.
• Try a different wall socket. Plug a lamp into the one you've been using to confirm it's live.

If another known-good charger works, replace yours. Apple 96W USB-C chargers are £79 new; third-party MFI options are £30-40.

2. The port

USB-C / Thunderbolt ports collect pocket lint, dust and dog hair. A blocked port can't seat the connector properly, and charging is intermittent or fails completely.

• Use a dry wooden toothpick (not metal) to gently hook out anything in the port.
• Blow a short burst of compressed air (can upright, short bursts only).
• Try a different port on the MacBook — most have 2-4 USB-C ports. If only one port works, that's a damaged port, not a charger issue.

On older MagSafe models, the magnet surface attracts fragments of metal; wipe with a dry cloth and check the small pins are clean and unbent.

3. SMC reset

The System Management Controller handles charging, battery and thermal behaviour. When it gets confused, charging stops. Resetting it fixes a lot.

Apple Silicon (M1, M2, M3, M4) MacBooks:

• Shut down fully.
• Wait 30 seconds.
• Power on. That's it — Apple Silicon resets SMC automatically on boot.

Intel MacBooks with T2 chip (2018-2020):

• Shut down.
• Hold Control + Option + Shift (right side) + Power for 7 seconds.
• Release all four keys together.
• Wait 10 seconds, then power on normally.

Older Intel MacBooks (non-removable battery):

• Shut down.
• Hold Control + Option + Shift (left side) + Power for 10 seconds.
• Release all, power on.

About 30% of "won't charge" issues clear with an SMC reset.

4. The battery itself

MacBook batteries are rated for 1000 cycles before they drop below 80% capacity. If you've had the laptop 5+ years or use it heavily on battery, the battery itself may be the fault.

Signs the battery is the problem:

• Laptop runs fine on charger but dies instantly when unplugged.
• Battery Health shows under 70% capacity.
• Cycle count above 1000.
• Battery is visibly swollen — the trackpad clicks strangely, the case flexes, or the laptop won't sit flat on a table. This is urgent — a swollen battery is a fire risk. Stop using the laptop.

Battery replacement at Apple: £199-249. Independent repair with genuine Apple cell: £130-180. Third-party aftermarket: £80-120 (quality variable — cheap cells can swell within a year).

5. The logic board (rare but possible)

If charger, port, SMC reset and battery age all check out and the laptop still won't charge, the charging IC or a related power component on the logic board has failed. Symptoms:

• Laptop charges erratically — sometimes works, sometimes doesn't.
• Charging stops above a specific percentage (e.g. never goes above 45%).
• USB-C port gets noticeably warm when charging cable is plugged in.

This is a board-level repair. The common failure is the U2 / Tristar chip that manages USB-C power negotiation. It's replaceable on the bench with a hot-air station by a skilled technician — not a DIY job.

When to send it in

If you've tried a different charger, cleaned the port, done an SMC reset, and your battery isn't obviously worn, the problem is likely on the logic board. We diagnose MacBook charging faults on the bench — free diagnosis, no-fix-no-fee. Most jobs turn around in a week, and logic-board charging IC replacement typically costs £120-180 including parts, vs Apple's £800-1500 "replace the whole logic board" quote.