How to Troubleshoot a Power Issue

Power issues are annoying. Either your laptop shuts off suddenly because the power cord unplugged, the battery craps out after 20 minutes, or it just doesn’t turn on at all..

Like all laptop manufacturers, Apple sometimes has battery issues. Or power adapter issues or power related logic board issues. How can you tell what exactly is wrong with your laptop that either won’t run or has a chronic dead battery?

Here’s how you can troubleshoot a bad battery, bad power adapter or bad logic board and is it covered under warranty / AppleCare.

To successfully figure out what’s wrong, you need to eliminate the three main parts of a laptop’s power system. Its either the power adapter, the battery or the logic board (motherboard).

Is it the Power Adapter?

Power adapters are easy to figure out. Take out the battery and see if the laptop will run from the power adapter and the power adapter only.

If it does, the power adapter is good.

If it doesn’t, try to run your MacBook with a different power adapter (one that works) and no battery. If it runs then, you’ve got a bad power adapter. If not, skip to the logic board section.

To fix this, you’ll need to replace your adapter. Just remember a MacBook takes a 60W Power Adapter and a MacBook Pro takes an 85W Power Adapter.

Is it the Battery?

Troubleshooting a bad battery can get a little tricky, only because it could just really need a charge. For this, you’ll need access to another Mac and battery. A friend’s will do just fine. There’s three things that could go wrong with a battery. Either it won’t be recognized by OS X, won’t charge or won’t last long.

Battery not recognized:

First, look in the Menu Bar, near the clock. Does the battery symbol have an X in it? If so, that means your Mac isn’t recognizing it.

Put the questionable battery into your friend’s MacBook. Does it still have an X? If so, there’s something wrong with the battery. If it looks normal, read on.

Battery won’t charge:

Try to charge the questionable battery in your friend’s Mac. If it charges, that’s a good sign the battery is OK. If it doesn’t then your battery is likely bad.

Put the questionable battery back into your Mac. Is it recognized? Will it charge? If so, that’s a good sign. If it doesn’t charge in your MacBook but charges in your friend’s and you know your power adapter is good, skip to the next section.

If your battery charges and is recognized but doesn’t last long, your battery could either be bad or just at the end of its lifespan.

Battery doesn’t last long:

To check your battery’s statistics, open System Profiler by clicking the Apple in the upper left hand corner and choosing “About this Mac”. When the About This Mac box pops up, click the “More Info…” button to open System Profiler.

In System Profiler, on the left hand side, click “Power”. At the top will be the Battery Information. The information you are looking for is:

- Charge remaining.
- Full charge capacity.
- Cycle count.
- Condition.

A battery that doesn’t last long has a low Full charge capacity. A new battery usually has a number in the mid 5000′s for a full charge capacity, the exact number depends on your model and battery type. Any number less than 2000 is low and you’d notice it draining quickly.

Now that you know your battery’s capacity, look at the cycle count. If its in the high 300′s and your charge capacity is low, your battery isn’t bad – it’s just nearing the end of its life. However, if your cycle count is under 100 and charge capacity is super low (1000 or below), you may have a defective battery.

To tell whether a battery is healthy / normal or not, check the Condition reading. A “Check Battery” reading usually means defective while Fair or Poor could just mean the battery is nearing the end of its life.

Replacing a battery under warranty:

Apple only covers defective batteries if you are under 300 in your cycle count (and your warranty is still in effect). So even if your battery is defective, but you used up too many cycles, they won’t replace it.

Is it the Logic Board?

Logic board power issues come in three flavors. Either the power adapter won’t power the laptop (assuming the power adapter is good), the battery doesn’t charge, or your Mac simply doesn’t turn on at all.

Testing for the first issue is easy – take out the battery and run your MacBook without it. If it won’t power on with a good adapter, its a logic board issue.

Testing for the battery is also easy except you’ll need a friend’s Mac. See if your Mac will charge their battery and see if their Mac will charge your battery. If it’s a logic board issue, your Mac won’t charge either battery while their Mac will charge both of them.

In the third case, its pretty obvious if the Mac refuses to turn on at all.

In any case, you’ll need to replace the logic board. This is an expensive repair, but fortunately its covered under warranty / AppleCare. Take your laptop to the nearest Apple Store or call Apple to schedule a repair.

Just remember, if your Mac doesn’t turn on at all because of liquid damage, it is not a covered repair.

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