Dell XPS m2010 won't start up, blue power light and Bluetooth light stay on

[jimab]

dell xps m2010 wont start up ,blue power light and bluetooth light stay on,i have been searching posts in other forums as well as this one and i thought i`d narrowed it down to the graphics card,i was right to an effect,my approach was to take the xps apart following dells website documents,while i had the top (dvd drive) off ,i noticed that the graphics card screws were really loose (this was my first job)...i tightened these.The top(dvd drive ) i re-connected ,but propped it up at an angle so i could still see motherboard and parts,(warning!be carefull!!)electric!! ...attached power cable and pressed power button after half a dozen times pressing this it came to life.I noticed my fans were working and thought this might not be my motherboard after all ,no overheating happening...then it froze on windows xp ??it was a start !another 6 to ten times pressing power button it worked again this time not freezing.went into bluetooth with usb mouse and paired keyboard ,made system restore point and restarted .It took maybe 4 times with it being glitchy(freezing ..not powering up) ,but when it does load xp without freezing try restarting windows xp and then it eventually finds its feet!!!my xps 2010 is running ok now.jimb