what i did to SMC and reset MBP without replacing battery, without replacing boards or power supply. you need a precision 1.6mm Phillips screwdriver and a 3-prong cell-phone-type screwdriver. my battery was fine, so was the power supply and DC board. if SMC doesnt work - open case, disconnect battery, hold power down 5 sec, attach power adapter. remove power, install battery and back, do SMC process, re-attach power adapter, power down system, reboot by holding power down. good to go. good luck. it worked for me.