i have to 2nd Yaya's recommendation. i had mechanical problems (fan on macbook would not shut off). MacFixIt web site had the combo load recommendation and it worked as well as a few others.
i also re-set PRAM (or whatever they're now called) by turning on mac with control-option-P-R held down for 3 sets of chimes. i also reset battery controller, SMC. this is reset by turning off laptop, removing battery and then holding down power button for 5 sec. then reinstall battery and power up. if laptop battery not re-charging properly, the SMC should be reset.
now all works fine.