MacBook only works when plugged in – what to do?

If your MacBook only starts when plugged in or shuts down immediately when disconnected, this indicates a hardware problem. In many cases, the battery is affected – but not always. The logic board, the power-on-a-microcontroller (PMIC), or internal sensor malfunctions can also cause this behavior.

Below you will find the most important possible causes and first steps for diagnosis.

🔧 Possible causes

1. Defective or aged battery

Many MacBooks will no longer start from the battery if it is deeply discharged, damaged, or completely worn out.

Signs:

• Battery not charging
• “Service Battery” or “Replace Now” notices
• Mac shuts down immediately without power adapter

2. Error in the charging IC (Power Management IC / PMIC)

If the charging chip does not control the charging process correctly, the MacBook may not recognize or use the battery.

Signs:

• Battery present, but system shows 0%
• The device switches off immediately, even with a new battery.
• Charging process does not stop or start

3. Flex cable to battery damaged

A faulty battery cable can prevent the MacBook from receiving power from the battery.

4. SMC error (System Management Controller)

The SMC controls energy and charging functions. A fault in it can also trigger this behavior.

5. Logic board defect

In case of liquid damage or corrosion, the power supply to the logic board can fail.

🧪 Initial solutions (that you can try yourself)

1. Perform an SMC reset

Often a simple reset is enough to fix energy problems.

For Intel MacBooks:

• Shut down Mac
• Shift + Control + Option + Power for 10 seconds
• Release, start Mac

(There is no SMC reset on M1/M2 – Apple does it automatically.)

2. Check the battery status in the system

• Click on the battery icon in the top right corner.
• “Service recommended”? → Battery probably defective

3. Try a different charger or cable.

A faulty charger can deliver incorrect values ​​→ battery will not charge.

4. Check the battery inside the casing (if possible)

• Bulging/inflation? → Stop using immediately
• Are screws loose or is the battery connector disconnected? (only for experienced users)

🛠️ No improvement? Then a diagnosis is needed.

If the above steps do not help, the error usually lies with one of the following:

• defective battery
• Charging electronics (PMIC)
• Logic Board
• Short circuit caused by liquid or corrosion

In these cases, a professional diagnosis is necessary, as component repairs are highly specialized.

🏆 Come to Macsclera Vienna

We offer:

• Professional battery and logic board diagnostics
• Repairs at the component level
• Rapid fault analysis
• Fair & transparent prices

📍 Währinger Straße 125, 1180 Vienna

Bring your MacBook in – we’ll find the cause and repair it reliably.