Mountain Lion (10.8) Unable to sign into App Store, iCloud or FaceTime

[B-San]

try this
quote from tonymac:
Issue: Can't log into iCloud.
Solution: Update to latest Chimera

Issue: Still can't log into iCloud- first time setting it up on any device.
Solution: Change /Extra/smbios.plist serial number- for example:

Code:

<key>SMserial</key>

<string>G88451235J4</string>


change 845123 to something between 750xxx to 905xxx

Code:

<key>SMserial</key>

<string>G88451005J4</string>


then reboot. After setting it up for the first time- you will be able to return your serial number to the previous MultiBeast default.

This worked for me on an older system running Mavericks 10.9.5. For whatever reason, it originally had a 10 digit serial # as opposed to 11. I changed the # and also added another digit and now I'm able to log in to iCloud as well as the app store. Thanks!