Hoping you have fixed this by now, but if not, try this:
Remove the battery.
Remove the hard drive.
Restart it and press the BIOS keys Control-Alt-Esc to see if you can enter the setup screen.
If you can not enter the setup screen, and can not test the power supply output (be careful, voltmeter probes may short or damage the plug), it might be a good candidate for an iFiXiT teardown guide.
Hope you can get it booting, it would make a good "netbook", especially running an easy version of Linux like Ubuntu or Linux Mint.