when i startup tincat2(athlon firebird, asus motherboard, 1.3gb sdram), i get a sort of chittering sound from the speaker(the machine speaker, not the sound apps setup) during post and am unable to enter bios setup. what appears to be happening is that the keyboard isn't getting support(ps2 logitech-though i have already switched this out and no improvement). i first noticed this when the keyboard just stopped working during a session. i had to reset and then got no response from the keyboard when i tried to login-reset and no response again when i tried to enter bios. i also noticed that when i shut down(before i kill the power at the power down prompt) there is line noise coming through the stereo i use for sound-not just a 60 cycle buzz, more varied). any thoughts appreciated as always.

You might try resetting the bios(remove motherboard battery for a couple minutes) and also check for any loose connections or bare wires. Unplug your power cable before doing any of this. If that doesn't work, strip the system down to bare necessities(Motherboard, Processor, RAM, Vid card, Keyboard) and go from there one piece of hardware at a time to find out what's causing the prob.