PSU question an HDD failing

[aspiregamer]

I turned on my PC today to it failing to detect a hard drive. I assumed right away that it was my Seagate Barracuda 7200.10 that I had had issues with before that turned out to be the sata cable. I then suspected that it was the new WD black 750 that I got about a week ago. But both slave drives booted seperately with my C: but not when all three where plugged in. My pc ran fine before with 2 7200RPM sata drives and 2 5400RPM IDE drive but just recently stopped being able to run 3 7200RPM sata drives. I have a Antec Basiq Power 550watt PSU that I purchased on 5/28/08. Its been running Id say 6-7 hours a day and once in a while has been on overnight. Could the issue I am having power issues due to capacitor aging? on the Thermaltake PSU calaculator page it says min psu watt 435, recommened 485, with 25% capacitor aging. If my PSU runs at 85% EF that would be 467watts. So Im thinking this is the issue, Also I have notice my rear fan when booting delays in rotating but lights up when my pc boots.

AMD Phenom x3 740 Heka [stock]
DFI LP 790FX-M2RS AM2+
Corsair XMS2 4GB[1GBx4] DDR2 800
Sapphire Radeon HD 3870 GDDR4 [with Zalman VF1000]
Edimax Wireless-N PCI Card
Creative Audigy2ZS PCI
WD Blue 250GB 7200RPM Sata
WD Black 750GB 7200RPM Sata
Seagate Barracuda 250GB 7200.10 Sata
LG DVD-R/RW Drive
2x Logisys Cold Cathode Lights

 

[madhatter256]

I would replace the PSU and see if the problem persists or not. If it continues even with a new PSU, then I would suspect the motherboard.