Оригинальный сообщение: Brian ,
Hey, I did an SMC reset but did not resolve the issue. Then I just reseat the cable from Trackpad to Motherboard. Then it works perfectly now. Power on using power button as normal. I found that there is a small dirt particle at the cable connector at Trackpad. Blow that particle off then issue resolved. Poor Apple Technicians. The owner told me that Technicians did try out a new battery, new Megasafe board and concluded that motherboard needs to be replaced. The original owner decided to sell it to me quite cheap.