CPU fan dead at boot only & rpm info not detected

[Postal64]

Weird and "interesting" situation: My CPU fan (Zalman CNPS 9700) hesitates to start at boot-up. Repetitively, the fan attempts to spin (slight impulses) until it decides to spin normally after boot-up is completed (bios "Fan failed" message included!). Thinking the fan was the issue, I replaced it with an Arctic Cooling Freezer 64 Pro and the problem remains the same. In addition, the new fan isn't even detected and reports 0 rpm (Even when it decided to spin after boot-up). The new fan has a 4-pin lead and my Asus A8N SLI Deluxe MB has a 3-pin CPU fan header (Don't think this is a problem, right?). I previously have been running this system for the past 3 years without any issues.

So the problem is dual: CPU fan won't start at boot and rpm info isn't being detected.
I don't know how to troubleshoot what's wrong here. Where should I looking into? PSU? MB? Bios? Where to start?

Thanks,
Greg.

Current PSU Values:
V-core: 1.34v
3.30v, 5.08v, 12.10v

Here's my gear:
Asus A8N SLI Deluxe
AMD Athlon 64 X2 3800+ Socket 939
OCZ Technology 2GB PC3200 DDR
x2 EVGA GeForce 7800 GTX 256MB in SLI
Enermax PSU Noisetaker 701AX (600W)
NEC ND-3550A 16X DVD+/-R Burner
Win XP Pro

 

[Postal64]

Things I should have done from day one: Clearing CMOS. All came back normal after that. Probably the Bios settings that got corrupted. Now, I just have to return the new cpu fan to Newegg...