When I turn on my computer, the power light turns on, and I can hear it starting up like normal; but the monitor, keyboard, and mouse make no response. By this I mean, nothing is displayed on the monitor, the laser mouse doesn't turn on, and the lights on the keyboard don't turn on. I've tried switching the monitor keyboard and mouse with others, so they're not the problem.
Also, when I turn it off, the power light (on the computer) stays on. What could be causing this? This happened with no warning, and no major software changes were made before the problem occurred.
MB: Pc Chips A11g V1.0
VGA: NVIDIA GeForce 6100
CPU: AMD Athlon(tm) 64 Processor 3800+, MMX, 3DNow, ~2.4GHz
OS: Windows XP
Memory: 1GB Kingston