We checked the fan, it's running fine. The grinding noise seems to be teh floppy drive, when we recconnect it the noise starts again, disconnect it and the noise is gone. But the computer still won't boot up. The computer was built by my son 2 years ago, has worked great until yesterday. Reading the invoice from the parts list, it has an AMD-zXP-2700+ 2.167 GHz, 333 MHz, FSB , hard drive is a Maxtor 40GB 7200 RPM ATA100, it lists the video card, the fan, the floppy drive, the CD-RW Burner, and something called a 64MB GeForce 4 MX-440 8X AGP. I'm not sure if that's what you mean by specs. When we hit the power button, the lights come on, the fan comes on, the monitor stays black.