Everything started with Nimble Quest, the worms-like game. While on the iOS I was getting the coins from my Guild, in my iMac I was not getting any coins.

Also, Facetime was working correctly on my Mac Book Pro, as well as some additional iCloud utilities like Back My Mac, but I was unable to log on in my iMac. On both machines the App Store and iTunes was working correctly.

The next clue was the Mac OS version. In the faulty machine it is install Lion Mountain (10.8.4), but on the Mac Book Pro I still have not upgraded, so it seem there is no trouble with Lion.

After applying some recommendations from the forums: Log out, log in to iCloud, update your data on the web side of iCloud, things were not getting better, but after reading this post, I remembered after the last servicing by Apple my Mac OS Mountain Lion came back from service with no serial number. It seems this is a problem with some Mac OS versions and some applications. The recommended solution is to go back to Apple Service and ask them to update your firmware with your serial number. Unfortunately my iMac was out of support and I did not move the machine so I decided to upgrade it myself.

So, if you decide to take the risk and do it yourself (probably this is unsupported by Apple) you should follow the next steps:

First of all, check you have no serial number in your firmware checking in the System > About your Mac > More Info… you’ll get a window like this, stating your Serial Number is None or (in my case) System Serial#:

Mac OS without serial number

Mac OS without serial number

So, if this is your case, you have to write your serial number in your firmware. If you decide not to go to an Apple Support centre, find your serial number using this Apple page.

Download an unsupported, Apple only tool called Blank Board Serializer that will enable you to write a new serial number if the main computer board has none.

Once downloaded, uncompress the file and write the .dmg file to a CD disk using Disk Utility (some people report you can use a USB memory, but the CD way is the recommended way).

Insert the CD in the CD/DVD slot and boot the computer pressing the key C to allow the computer to boot from the CD.

Alternatively, you can use blank board serializer 3t106 063-7137.zip extract the file 063-7137-A.dmg blank board serialiser using Disk Utility, restart holding alt/option, agree to the terms, enter the serial and restart.

After loading the tool, allow some time to bind the bluetooth keyboard or mouse to the computer and follow the tool instructions.

Some caveats:

  • This is unsupported and I’m not responsible for anything.
  • The tool can only set the serial number on a main board that has no serial number, so if you set the wrong serial number you wont be able to correct the error and will have to visit an Apple Support Service.
  • Some older computers may not be supported by the Blank Board Serializer, so if it does not work, write it in the comments.
  • Some newer hardware may not be supported by none of the tools, so check the comments.

After setting the number, you will be asked to reboot and you’ll be able to check if the process worked correctly in the same screen. In my case, it was corrected (number anonymized just-in-case):

Mac OS with new serial number

Mac OS with new serial number


And of course, now all the iCloud services work correctly!

Feel free to comment here.