Migration Assistant

Being that we deal with Macs on a large scale, we often come across situations where, due to either the need to upgrade to a later generation or their current Mac becoming ill, data needs to be transferred from one machine to another. There are a number of different ways this can be done, but before I get into the details, heres a little disclaimer.

Please Note: The migration or transferal of data from one machine to another is not a fail safe system. OS X’s built in Migration Assistant is designed to transfer data from a different Mac with a maximum backward compatibility of 2x operating systems. It may be possible to extend this further, but it is not advisable because of potential software problems that could be caused. When dealing with older machines running legacy software, it is advisable to either delete the software not compatible with the newer machine, or do a manual transfer instead of using the Migration Assistant to prevent possible problems. Some software faults can depict themselves in a way that appears to be a hardware fault (i.e. flickering screen, jittery curser, loss of bluetooth or wifi, locking up or slowing down, etc), making it difficult to diagnose if you haven’t used the machine before to confirm its hardware stability. Before starting a migration, it is advisable to remove all passwords from accounts on your old machine, as this is one factor that has been seen to repeatedly cause problems from time to time. It is always necessary to disable FileVault on any account being migrated, as no data can be accessed from that account unless it is disabled.

Now that thats out of the way, lets get started with option number one, Migration Assistant:

(The images below are used from a later software version, so if you are running 10.6 or earlier, the windows and text may not look exactly the same, but the process is the same)


Migration Assistant can be accessed in one of two ways. Either through a fresh OS install during the initialisation process (after you select the language you want, it will ask you if you want to transfer any data from another Mac or hard drive) or through an OS with an account created already.

Mavericks Fresh OS

Mavericks Fresh OS

Initialised OS Sample

Initialised OS Sample

Either way, all that is required is for you to connect your old hard drive (in an external enclosure via USB or Firewire), or connect your old mac in target disk mode to your new mac via Firewire, or Thunderbolt. then click ‘transfer’. you can select specific types of data to transfer if you don’t need/want it all transferred, or you don’t have the space for it all on your new computer. simply deselect the options from the list based on what you’d like to transfer as seen below. You can also expand each user account to select specific information within each account.

Select Data

Select Data to copy

If you choose the to use the latter connection type via ‘Target Disk Mode’ instead of with an external drive, then follow these steps to connect your machines together.

If you have an earlier machine, it can only be done via Firewire 400 or Firewire 800. Whereas, if you have a machine from 2011 or later (all except the Mac Pro range), then you can also connect up via Thunderbolt. But the process to initialise Target Disk Mode is the same for both connection types. (please also note, Thunderbolt is different to Mini-Displayport, the latter will not work in this process)

First, ensure your Mac is plugged into the mains if it is a laptop, as the migration process can take a few hours to complete depending on how much data you have to shift across. If you don’t plug in the computer and the battery dies during the process, it will cause corruption on the new machines drive, and it will most likely need to be reformatted before attempting the migration again.















  1. Connect a Male-to-Male Firewire/Thunderbolt cable from one mac to another.
  2. Hold down the letter ‘T’ key on the keyboard of the old Mac and turn it on while still holding the ‘T’ key.
  3. Hold the ‘T’ key until after the machines start up chime occurs and a floating firewire/thunderbolt symbol appears.
  4. Turn on the second Mac and follow the steps above to migrate using the ‘From Another Mac’ option.

Option 2: Clone the entire hard drive

Cloning from one drive to another is another option when upgrading from one machine to another. The upside is that it can be done in a few hours, and if you select a root level clone, it will copy absolutely everything from the old drive onto the new. The downside is that its not failsafe, as it can miss files or partially transfer files, which can cause OS problems or corruption of data. But most applications for cloning will do a comparative check of the data on both drives before finishing the clone to ensure its as accurate as possible.

If using this method, you will need a separate bootable drive (you can boot Macs via external drives. Intel machines via USB or Firewire, or PPC machines via just Firewire), because the application needs to be run from an operating system. I would also recommend running both disk repair and permissions repair on the drive a few times after the clone to help check and clean up any organisation problem with the OS files.

This method is not as straight forward for the average user, so i will not detail the entire process here, but there are many other detailed websites out there with all the details. Typically on a mac, the best free cloning applications are SuperDuper and Carbon Copy Cloner (CCC).

Option 3: Drag and Drop

The third and final option would be to drag and drop data from one hard drive to another.

Target Disk Mode is not only used when migrating data, so you can use the described method above to enter Target Disk Mode on your old hard drive to get the hard drive to mount on the desktop of your new mac to access the folders.

This method is the last of the three suggestions because it can be very difficult for someone not used to the way the data is stored and organised on a hard drive, but it can also cause many problems if the wrong data is copied, or if system folders are deleted or replaced on your new machine. This can cause software problems, or potential locking up of the entire machine if done wrong. Also, many applications have hidden permissions files and folders, as well as different locations for storing data used to make the programme work, so cannot simply be dragged and dropped from one machine to another. Still other applications require authentication when being installed, and can detect when they are copied or moved, and will need re-authenticating when moved from one machine to another.

If you use the ‘Drag and Drop’ approach, i would always suggest installing your applications from their original install disks, then adding your stored files and folders (such as music, documents, media, etc) from your old drive onto the new one so no root folders are being accessed, and you don’t create more work by messing around with the operating system.

I hope you don’t have to use these methods for any other reason than upgrading to a fancy new Mac (if your old mac has died, whether its been run over by a truck, or your housemate accidentally spilled an entire bowl of spaghetti bolognese on your laptop, i’m sorry…)

But i hope this proves helpful when deciding how to get your data from one machine to another. You can also use these approaches when simply upgrading your hard drive capacity on a mac, which is always a good thing.

On another note, because of the construction of a hard drive, its mechanical parts are very fragile. It is very common for them to fail and die, so it is always advisable to keep a backup of all your data. Macs have had a built in tool called ‘Time Machine’,  first available from 10.5 Leopard, which is a great automatic backup tool to remind you to save your important files.

As always, if you have any questions, please let us know and we will do what we can to get an informative response to your question. Macs are our specialty, but amongst our enginerds are many varying hobbies and skills that may come in handy with answering your other questions too.

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Easter : A question of faith


The existence of Jesus of Nazareth as an historical character who lived and died by crucifixion at the hands of the Romans, is not disputed by Christians or historians. The question surrounding this controversial figure is who he was. Was he who he said he was; God become a man, or was he only a man.

At Easter, more than at any other time, this question should be most pressing on our consciousness because Easter is a celebration of Jesus’ resurrection; His miraculous return to life after being dead for three days.
It’s a question of faith, not faith that Jesus existed, but faith that he was not mad or a liar, but who he said he was.

Unpopular as it is increasingly becoming to say, I believe that Jesus was God become man, born for the express purpose of dying in our place; my place, to take the punishment for my wrongs.

Jesus of Nazareth was not ashamed to be tortured, humiliated and crucified for me. If this offends anyone, that is not my intention, but I will not be ashamed to honour Jesus at Easter time for this ultimate act of love and sacrifice.

I wish everyone who reads this a Happy Easter. I hope you know, or come to know, just how much God loves you.

Nick Gillard

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Apple part numbers explained

Have you ever been confused by why the same Apple part is referred to by different part numbers?
All Apple service spares are identified by Apple part numbers but there are different types of part number and if you are repairing Macs specifically, it is useful to understand the way they work. The following article explains the different types of Apple part numbers, how they work in practice, and some of the oddities that arise from this.

There are two groups of part numbers which we call the GSX numbers and the production numbers.

GSX part numbers
GSX part numbers are the ‘official’ part numbers because within the closed citadels of Apple Authorised Service Providers (AASP), only the GSX part number is used or recognised. As far as we know, there is no official term to differentiate them from production part numbers.

GSX numbers define a logical part rather than a physical one and never appear on the part itself. They represent a part with a particular specification. What this means in practice is that although a particular part may go through multiple tweaks and revisions during it’s life span, if it’s specification and definition are unchanged, the GSX part number stays the same. We refer to them as GSX because they are the number used to identify the parts on Apple service manuals and when AASPs order through Apple’s Global Service Exchange web site (GSX).

Another implication of this is that parts only have a GSX part number assigned if they are available as a service spare. An example would be a MacBook Pro display which is only supplied by Apple as a complete assembly. This has a GSX part number but no such number exists for the components within it i.e. the lid panel, glass panel, LVDS cable, iSight cable, iSight board, LCD panel or hinges. For such assembly components, only a production part number can be used to identify them, if one exists.

GSX part numbers are of the format 999-9999. The first three digits identify certain categories of parts and the last four are assigned sequentially and therefore give an indication of the chronology of release.
There are a relatively small number of values used for the first three digits. Here are some examples although this is not a comprehensive list.

922- , 923- : Not available through GSX as exchange. This is referred to as being stock only.
076- : generally used for kits or tools. Also stock only.
661- : Available to AASPs as exchange through GSX.

If the specification for a particular part changes during its life span then a new GSX part number will be assigned as a substitute part number for the original. This can happen when a new product range uses an improved design of a part but that part is still backwardly compatible with the previous range. In this case, rather than stock and supply two different service parts, Apple will define a new GSX number as a substitute for the original. This is why there can be multiple GSX numbers used to refer to the same service spare e.g. On thebookyard.com.

If a particular part is used on a subsequent product range but the specification of that part remains the same, the GSX number remains unchanged.

Production part numbers
Production part numbers are those that actually appear on the part themselves and uniquely identify a particular design or revision of part. They are of the format 999-9999-A where the last letter is used to identify minor revisions. If Apple sources a part like a power supply from multiple companies, each company’s version will have a different production part number printed on it. Every time there is any change to the design or manufacturing process, the part number on it will change.

There can therefore be many different production part numbers appearing on different examples of the same part i.e. a new service spare from a Apple may have a different production part number on it to the number on the original part it is replacing.

Most Apple service parts will have a production part number on it. This most commonly starts 820- or 821-.
Other common prefixes are 630- and 632-. In some cases a single part, like a flex cable, may have two different production part numbers on it. We are not really sure why this is.

Larger assemblies which comprise multiple components, such as top case assemblies or complete displays, may have multiple production part numbers in different places and this is because individual components used to produce the whole assembly may have their own numbers.

Conversely, sometimes different variants of the same part will carry the same production part number. This is most notable with logic boards. It is usual for different speed logic boards within the same product range to use exactly the same PCB. The only difference is that a different processor chip or GPU chip is fitted for different versions. In this case, the production part number screen printed onto the PCB will usually be the same for all processor speeds within that range.

Even stock parts available for purchase outside of the Apple channel such as optical drives or hard drives will carry an Apple production part number if they are from a Mac or an official Apple service spare. The part may be identical to the non-Apple numbered version but it may have been modified or loaded with firmware specifically for Apple.

An example would be the Panasonic UJ-875 that Apple used in some of the Intel iMacs. Stock Panasonic UJ-875s could be bought on eBay or from Panasonic distributors but these would not work because Panasonic produced a modified version for Apple with a longer pickup distance to allow the drive to be set back further within the case. Even more confusingly, Panasonic also supplied Apple versions with the normal pickup distance for use in MacBook Pros. The key to identifying which version was with the production part number.

Our own comprehensive Apple service spares web store allows parts to be located by GSX or production part numbers. Another way of identifying parts is by the parts own serial number but that’s another blog post …

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