No beep, fans are spinning: Mobo/CPU or PSU?

[nsn]

My homebuilt computer has worked perfectly for a couple of years, but recently stopped working.

It won't boot/give me a video signal, but the CPU fan, PSU fan, GPU fan and case fans are still spinning, the HDDs spin up and the LEDs are working.

Processor: Intel Core 2 Quad Q6600 2.4GHz Socket LGA775, 8MB, w/fan
Motherboard: MSI P35 NEO-FI, P35, S-775, DDR2, PCI-Ex16 1333FSB, ATX, GbLAN, Firewire
Memory: 2x Kingston DDR2 HyperX PC8500 2048MB CL5
Graphics: MSI Geforce 8600GT NX8600GT-T2D256E-OC
Case: Antec NSK4480B New Solution, 1x120mm Tricool 3-speed fan, 380w PSU

I should mention here that I discovered and cleaned out some serious dust bunnies from the CPU fan some six months ago, which may have fried the CPU. But like I said, it was working fine until this week.

I've gone through the troubleshooting guide for boot/video problems:
- I've connected the system speaker to check for beeps, but there are none.
- I've also tried removed everything but the CPU, the CPU fan and case fan, but there are still no beeps.

As far as I've understood this translates to dead motherboard. However, I don't have a voltmeter - could it be that the PSU is at fault?

Any help or advice is appreciated

 

[nsn]

Update: I did the paperclip test and the case fan spins, so the PSU seems to work fine.

After reconnecting the PSU to the motherboard both case fans and CPU fans are running. I have also tried removed the HSF to check the CPU, which still heats up. Still no beeps though.

Input?

 

[DoomsWord89]

Sounds like it may be your MOBO, mate.