MacBook Pro A1502 weird power issue?

The A1502 designation is too vague and covers MBPro 13" models from Late-2013 to 2015.

Most likely this laptop has a hardware issue, but it is hard to be certain what that issue is. A bad battery is a very likely possibility, but so is a Logic Board issue (at least these are the two most likely hardware issue). Some of these models are now "Obsolete", so no hardware repairs are available through Apple. The 2015 model is considered "Vintage" (perhaps also the 2014 as well), but repairs are only possible if the necessary part(s) are still available.

Disconnecting the battery from the Logic Board will eliminate the battery from the equation and may allow the laptop to run, however, the fan may run at high speed and the system may run really slow...the main point is that the system continues to run since it is not doing so right now.

If the laptop is "Vintage", then have Apple or an Apple Authorized Service Provider evaluate the laptop to identify the most likely source of the problem. Probably anything other than a battery failure is not worth the cost to repair an older laptop.

jaerld wrote:

I just want to clarify: if I disconnect the battery and then connect the charger, but the MacBook still doesn't power on, can we conclude that the problem is with the logic board?

Not necessarily, but most likely. It could be a bad DC-In Board, plus any connected item could be causing a problem. I usually end up disconnecting everything from the Logic Board except for the DC-In and Fan, however, I don't recall whether this model will power on automatically when the charger is connected or whether there are power on pads located on the Logic Board (necessary if keyboard is disconnected). We usually have some old spare parts which we use for testing which helps out a lot so I don't always recall specifics especially when it was rare for us to do this.

Hello jaerld,

You've done some great troubleshooting on this matter. Thanks for taking those steps. We have a support article with troubleshooting for this matter, found here: If your Mac restarted because of a problem - Apple Support. Please take a look and complete any applicable and uncompleted steps from these guidelines which could help resolve that behavior.

"Check your software

If the issue is caused by software on your Mac, one of these steps might help:

• Install all available software updates.
• If your Mac suspects that a particular app caused the restart, it might ask whether you would like to move the app to the Trash. Click Move to Trash, then contact the software developer to see if a software update is available.
• Use safe mode to try to isolate the cause of the issue.
• Reinstall macOS. If the issue continues after reinstalling macOS, check your hardware.

Check your hardware

Learn how to check your connected devices and other hardware.

Check peripheral devices first

If you don't have any devices attached to your Mac, skip to the next section.

1. Shut down your Mac.
2. Disconnect all peripheral devices, such as hard drives or printers. If you have a desktop Mac, make sure that only a display, keyboard, and mouse or trackpad are connected.
3. Turn on your Mac.
4. Use your Mac for the amount of time that it would usually take for an unexpected restart to occur.
5. If an unexpected restart occurs, follow the steps to check the internal RAM and third-party hardware.
6. If an unexpected restart doesn't occur, turn off the Mac and connect one peripheral device at a time until an unexpected restart occurs.

Check RAM and third-party hardware

Certain models of Mac computers have removable memory (RAM). If you recently installed memory or a hard disk (or SSD), make sure that it's compatible and installed correctly. If possible, remove it and test with the original memory or disk.

Learn more

• If you continue to experience unexpected restarts, contact Apple Support.
• If your Mac is frequently restarting unexpectedly, it's important to determine the exact steps that lead up to the issue. The next time that your Mac restarts unexpectedly, record the date and time it occurs. These questions might help you diagnose the problem:
• Was the computer starting up, shutting down, or performing a particular task when the unexpected restart happened?
• Is the computer restart random, or does it happen every time you do a certain task?
• Does the restart happen when a specific external device is connected to your Mac or to a specific port?
• Learn what to do if your Mac doesn't turn on or start up.
• Learn about the screens you see when your Mac starts up."

If the issue persists, further assistance may be needed. We want to make sure you reach the right team for help with your Mac, so we recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support - Apple.

Thank you for participating in the Apple Support Communities and have a wonderful day.