4 Replies Latest reply: Nov 10, 2012 12:53 PM by TechJason
Elduke98 Level 1 Level 1 (0 points)

After 6 month of working, our MacBook Pro didn't boot suddenly. Nevertheless we have a 3 year guarantee and send it to the reseller for repair. They replaced the mainboard and send it back to,us.

But now, it boots every time in an EFI-Boot-Mode!

Also, it will not show any serial number of the MacBook Pro. Instead in the System Profiler we can read „Not available“.

How can we hide the EFI-Boot-Mode?

Is it correct that there is no serial number available after changing the mainboard?

Thanks for answering.

MacBook Pro (15-inch Early 2011), Mac OS X (10.7.4), Mainboard has changed
  • Kurt Lang Level 8 Level 8 (35,995 points)

    Don't know what you mean by EFI-Boot-Mode. Do you mean you get a bunch of white text on a black screen? If so, that's Single User Mode. And if it's doing that, I'm surprised the shop gave your Mac back to you that way.


    Turn the Mac off and then back on. Immediately hold down the Command+Option+P+R keys. Keep holding them through three startup chimes. Then let go and allow the Mac to startup normally. Does it boot to the desktop now?

  • Elduke98 Level 1 Level 1 (0 points)

    Thank you, Kurt.

    You're right, the Mac was starting in Single User Mode, and erasing the P-RAM has fixed that issue. The guy at Apple help desk couldn't give me that information.

    But still there is no serial number. I think, this was a #*?:;/&%-repair of my reseller! I have to send it back for accomplish it.

  • Kurt Lang Level 8 Level 8 (35,995 points)

    Having the serial number disappear is not at all unusual when a system board, and sometimes even when just the original hard drive is replaced. I wouldn't send it back just for that.


    There's really nothing wrong with it to be that way, other than making it slightly harder for you. Like when you call AppleCare. The first thing they ask for is the serial number, which tells them exactly what model Mac you're calling about.


    But anyway, it's not completely gone. The serial number is on the MacBook Pro in a few places. And as the page mentions at the bottom, it will also be on your purchase invoice for the Mac.

  • TechJason Level 1 Level 1 (0 points)

    When a Logic Board is replaced, it has to be serialized to show the Serial Number that it is attached to.  If the Authorized Service Provider doesn't do this, take it back to them and they can re-serialize it.  This is a fairly common issue.  It doesn't affect the computer in any other way.