well the 14" uses a 14 volt battery and the 12 uses a 10.4v so I suspect that your problem is there, at the battery and not with the power supply or the dc board. Usually what happens is the 14v battery fries the DC bus and the battery will no longer charge but the laptop runs ok otherwise. Basically the logic boards are not really interchangeable for this reason. You may be able to figure out a way around it though not sure how. But my 2 cents is its the battery not the power board.
Xplain's use of MacNews, AppleCentral and AppleExpo are not affiliated with Apple, Inc. MacTech is a registered trademark of Xplain Corporation. AppleCentral, MacNews, Xplain, "The journal of Apple technology", Apple Expo, Explain It, MacDev, MacDev-1, THINK Reference, NetProfessional, MacTech Central, MacTech Domains, MacForge, and the MacTutorMan are trademarks or service marks of Xplain Corp. Sprocket is a registered trademark of eSprocket Corp. Other trademarks and copyrights appearing in this printing or software remain the property of their respective holders.
All contents are Copyright 1984-2010 by Xplain Corporation. All rights reserved. Theme designed by Icreon.