if the external monitor works, there might be somewhere uncontacted, but it is very hard to find where and dangerous to open the case. if you don't care the risk, i can try to fix it for you.
thanks all you guys warm hearts, extra for Jumper.
Yes, I have tried the external monitor, it works.
Jumper, are you in Montreal? could you please contact me by my e-mail address: immigrate@163.com
Thanks for your great help in advance!