Mac running slow & not booting explained: Flashing folder icon, spinning wheel & Kernel panics

Mac running slow & not booting explained: Flashing folder icon, spinning wheel & Kernel panics

I have been getting a few Macs failing to boot recently and I thought it would be a good idea to explain a few things regarding this issue.

The first thing would to make sure we understand what some of the issues could be.

Also…

How to prevent further damage to you Mac or hard drive, because it could lead to data loss!

We’ll start with the dreaded Flashing Question mark icon.

This is one of the many reasons why your Mac is not booting.

Due to the nature of this issue we need to be careful as to know what the cause is before we go any further.

Flashing folder icon

This basically is the Mac telling you that is can not find a start up disk.

The start up disk is your Hard Drive (HDD), or in the newer Macs the SSD.

It’s the place where your Mac holds you Operating System (OS) and without it, the unit will just not boot.

Mac running slow & not booting explained: Flashing folder icon, spinning wheel & Kernel panics

Mac not booting

You might find your unit stuck in a so called ‘loop’ and showing the Apple Logo, a spinning wheel, and not going any further.

Well this could be one of several reasons.

Firstly it could be that the OS has got corrupted.

It could also be the Mac is finding it hard to read the rest of the OS to get booted up.

Mac running slow & not booting explained: Flashing folder icon, spinning wheel & Kernel panics

Kernel panic

This issue, although it too can lead you to a problem with the OS or the HDD.

It could also be an issue with hardware inside you Mac.

RAM, DVD, Cables in-fact anything that the Mac needs to operate & boot

Mac running slow & not booting explained: Flashing folder icon, spinning wheel & Kernel panics

Closer look at the Kernel panic screen:

Mac running slow & not booting explained: Flashing folder icon, spinning wheel & Kernel panics

Internal HDD cable

In the newer Uni-Body MacBook Pros I have found that the internal HDD cable can get damaged.

Not quite sure why or how, as I have inspected 100s of cables and there aren’t any moving parts, it’s a cable!

But alas they do ‘break’ so it might also be a cause.

I have also found that this problem can cause the HD to get corrupted, so data loss could be an issue.

And that’s not good at all!

Mac running slow & not booting explained: Flashing folder icon, spinning wheel & Kernel panics

What to do

We need to find the cause, and the only way to do this is to try to boot the Mac with an external HDD, a DVD (If you unit has one) the Recovery Partition in the newer Macs.

Once we have managed to boot up the Mac, we will need to check if the hard drive is being seen with the Disk Utility application.

Here you can verify and repair the drive, if the testing is taking too long (more than 20 minutes) then I would STOP and switch it off (see notes below)

Usually repairing the drive at this stage will make things better and your unit should start to work again.

If you have access to you drive at this point, it would be a good idea to backup as many files as possible just in case.

If you are not in a position to follow my notes above…

PLEASE switch off the unit and seek an engineer!!

…as the more the unit (or HDD) is used, or on, the worse it can make recovery of the data, if you need it.

Backup now!

As I see more and more units with these issues I urge you to do a backup.

It’s simple with Time Machine and no matter how many times you think “I will do it tomorrow”

…one day your Mac (or HDD) will crash and you will then need to do expensive data recovery to retrieve you photos, work, project, music etc.

Go backup now!!

Image renders by Sander Willems