fan start and stop can be a sign of corrupted bios. Try reset CMOs jumper and replace CMOs battery.  battery quite cheap $1-2.  Very unlikely recently replaced Corsair psu would fail.
I have an Inspiron 530 that I have upgraded over the last couple of years. Upgraded CPU to Q9650 Installed an SSD and 2 x HDD Upgraded to 8GB RAM This was all done months ago and has been working well. Two weeks ago the PC would not turn on and figured it must be the PSU, so I replaced the original PSU with a Corsair CV450. All worked well for 2 weeks. Suddenly, today, when I turn on the PC the fans start, then stop then start (i.e. the fans start pulsing every few seconds) and nothing else happens - no beeps nothing. I suspect it could be the motherboard or maybe the new PSU has failed. Any suggestions? (I am considering buying another PSU to test the failed PSU theory, but it all costs money - which I may be burning on this old PC).  
Inspiron 530 PSU or MOBO issue?