However, the above method of disconnecting and reconnecting MagSafe while holding the Power button was successful in starting up the Mac – with fans running at full speed and at reduced clock speed however.

Once the battery was removed you can press the power button but nothing happens. I experienced this scenario on an old MacBook Pro 2010 model after removing a swollen battery. The only way to stop the fans from running at full speed and to return the clock speed to regular performance is to install a new battery into the MacBook Pro. When the MacBook Pro does boot, the fans will be blasting at full speed for the entire time you are using the Mac ( resetting SMC or PRAM does not stop the fans running, only replacing the battery will).Īlso it appears that the MacBook Pro will reduce its own clock speed in this situation, thereby reducing performance. Release the Power button, then press the Power button as usual to power on the computer and boot the Mac.While still holding the Power button, connect the MagSafe power cable to the MacBook Pro and continue to hold the Power button for another 10 seconds.Hold down the Power button for 10 seconds and continue to hold it down.In this case, you can force the MacBook Pro to boot by following these steps: Then, when attempting to boot the Mac or pressing the start button, nothing happens. We are assuming the MacBook Pro has no battery installed in the computer, meaning there physically is no battery installed. How to Boot MacBook Pro with No Battery Installed So let’s discuss how to boot an older MacBook Pro when there is no battery present at all. Of course if you happen to have a replacement battery then you can typically just replace the missing battery with a working battery and the MacBook Pro will boot, but that is not always an option.

It turns out that some model year MacBook Pro computers will not boot with a simple power button press after the battery has been physically removed or disconnected. In this situation, if a battery is removed or totally dead and you attempt to start the MacBook Pro, nothing happens – there is no sound, no system boot, no startup chime, nothing.

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