A while back, I noticed something strange — I couldn’t log into the Messages program on my Mac Mini.  The Messages program interacts with iMessage, which means you can use it to send (essentially) text messages to any iPhone or iPad.  It’s great when communicating with people who are using iPhones because you have the full computer keyboard and display to use instead of an iDevice’s more limited capabilities.

But all of a sudden a while back, when I tried to log into Messages, it just spun and spun and spun but never got anywhere — just on the Mac Mini.  On my MacBook Air, it still worked perfectly fine.  I tried all the various solutions I found on the net — deleting various files and directories, logging in and out of accounts, etc.  But nothing worked … until … well, a story first.

Shortly into the life of my Mac Mini, the motherboard died, and Apple replaced it (free of charge).  But I had noticed something interesting — when I went into the About My Mac information display, my serial number was gone.  Apparently, when Apple installs a replacement motherboard, they have the ability to flash your old serial number to the new motherboard, but frequently don’t.  And if they don’t, the serial number is either blank or missing.  In theory, you don’t need a serial number: Apple tells developers not to rely on there being one.  But it may not actually be the case that you don’t need one.

I discovered a few people correlated the lack of a serial number with all sorts of problems logging into Messages.  Since nothing else worked, I figure that might be the problem with my Mac Mini.

So, the logical question was whether there was a way to restore the serial number.  And the answer is yes — there’s a utility floating around that will do that.  I found the utility and used it to restore the proper serial number to my Mac Mini.

And, amazingly enough, Messages worked immediately when I booted my Mac Mini that was now with its proper serial number.

If you are in need of this utility, you can find it on bit torrent.  Do a google search for “blank board serializer 3t106” to find it.  It’s a zip file that contains a DMG; you have to burn that DMG to a blank CD and then boot from the CD.  From there, the program asks you for your serial number and flashes the motherboard.

How do you know your serial number? One of two ways: if you’ve registered your Mac, it’s available online in the support system.  Otherwise, you have to visually inspect your Mac to find it.

As a disclaimer, my success does not guarantee yours, and this is an at-your-own-risk procedure. But if you are in need of a solution, it may be worth a try.