Lenovo 3000 J not booting up

Registration date
Monday November 5, 2012
Last seen
November 5, 2012
Long history on this but here goes. Current problem...When I turn on the PC, all lights come on, fans start to turn and sounds like drive starts but then everything stops and monitor goes black (power saver mode). Tried disconnecting power cord and holding down power button for 1 min then reconnecting and powering up...no help. Replaced power unit 4 months ago after failure of OEM power supply. Prior to that, PC would intermittently not power up then quit. Also prior to that, lots of freezing up and sometimes when powering up, hard drive would spin but never get to Windows loading screen. If shut down then powered up again would work. Changing power supply seemed to help. for a while. This happened a few times since power supply replacement. I'm an idiot and don't have my data backed up so it would be really cool if it is the MB and not the HD. Never had a blue screen that I know of. Kids haven't been helpful. Replacing computer this week. Hope to have access to data. Should I just bring in the HD and see if they can pull the data off and onto the new PC?

Thanks for all thoughts!