I have a test PC with a Pentium 4 CPU 1.3GHz, Intel D850GB, Nvidia GeForce 2 card, Western Digital 30.7GB hard drive, Goldstar CD-ROM, 512MB RAM(4*128MB), 3Com 3C905TX network card, Dynex FDD and Windows XP Professional SP2. No picture is displaying on the screen even though the fan is working.

The motherboard has a LAN and Audio controller, LAN is disabled in the BIOS. My father said it is the Hard drive but I don't believe so. The BIOS boot-up screen has a System builder OEM logo on it and the Video card is from Dell. I got the CPU, motherboard, and NIC from eBay. FDD and RAM from Amazon.com. The NIC is from a garage sale. The rest I had from disassembled PCs.

Some picture displayed earlier. How can I fix it?You should get a POST screen even without a hard drive connected. If you are getting no picture at all, it can be caused by a bad motherboard, a bad CPU, a bad video card, bad RAM or a bad connection.

If things worked recently and now they no longer do, I would check connections, RAM, motherboard and CPU in that order. The best way to test hardware is with spare hardware, if you don't have that available, ask some friends. Specifically COULD be a video card issue, but LIKE aardobard said try checking the connections to the ram, motherboard and cpu.

Also the parts you bought.. do they work in another pc, because i did notice you mentioned getting a couple of them from ebay.