Power on - fans spin up appropriately, appropriate lights light up.
The POST State LEDs on the motherboard light briefly in the following order, CPU for ~1 second, DRAM for ~1 second, VGA for ~2 seconds.
~10 seconds after boot the BOOT_DEVICE_LED lights for ~15 seconds.
~15 seconds after boot the system speaker emits one short beep, which according to the manual means "VGA Detected, Quick boot Set to Disabled, No Keyboard detected". Whilst I realize this may indicate a problem with the keyboard (could it be too old so the BIOS doesn't have the drivers for it? Do I need to get hold of a newer one?) I don't see why this would cause the monitor to display 'no input'.
The fans then continue to spin for over 2 minutes after boot, and there is no further change. The optical mouse lights up, as does the keyboard. The LED next to the Ethernet cable also lights indicating that it is 'LINKED'.
When I tried to boot the compute deliberately leaving the keyboard unplugged two changed occured. Firstly, the BOOT_DEVICE_LED stayed on for ~20 seconds, and secondly, ~25 seconds after boot (whilst the red BOOT_DEVICE_LED) is still on, the system speaker emits another sound at a slightly lower tone, which could also be considered 1 short beep. All other errors in the manual open with one continuous beep, followed y various numbers of short beeps, and nothing I've heard could be interpreted as continuous.
I have performed most (not all) of the steps on the '"System won't boot" and "no video output" checklist' thread, and have detailed which ones I have not, and why, below. If you think I should still perform them despite the reasons given then I will do so.
Mobo - Asus Sabretooth P67
CPU - Intel® Core™ i7-2600K overclocked to 4.60GHz
Memory - 8GB (2x4GB) Corsair XMS3
The above items were all installed on the motherboard before purchase, and the overclock was also done before purchase, by OverclockersUK)
Checklist items performed:
4. I believe so - not sure how I would go about verifying this, but the single beep, and the fact the VGA_LED turns off quickly suggested to me that it was.
5. Yes 6. Not performed, as these were installed before purchase, and the overclock done, I presumed that these were all seated correctly, otherwise they wouldn't have been able to do the overclock, as they wouldn't have been bale to boot to BIOS.
7. Not performed, for the same reason as above, when I purchased the mobo they were already inserted.
8. Yes 9. Not performed - I presume this was done, as the overclock was successful.
12. Thermal paste was already applied at time of purchase, so I guess its right.
13. Yes, one of the attached fans is plugged into the CPU_FAN sensing socket, the other into the Chassis fan sensing socket. Both draw power directly from the Power Supply however.
14. Not applicable.
15. Performed, none found
16. I believe I did, but again, not sure how I would verify this. I never felt any static shocks, touched the case regularly, and worked barefoot for what its worth.
19. Yes, no known good cord to compare, but as the computer boots I presume its alright. 20. Not performed - Not a clue, but as they performed the overclock before purchase, I presume so. 21. Not performed - I didn't want to do this, because I don't understand what it actually does, and didn't want to destroy the overclock they had done. 22. Not performed as I couldn't find (either in manual on physically) any sockets on the motherboard to plug a screen into?
As regards the bread boarding etc. I haven't performed that because I'm not confident enough too, and don't want to take apart any bits of the motherboard (chip, memory) that came installed in case I break something and the warranty on it, in case it is a problem with that, in which case I can simply return it and they can fix it.
I believe I've included all relevant information, if there's anything else that would be helpful please let me know.
Aha, problem solved, and I feel foolish. I had 3 sockets to plug the screen into on the GPU (and I did check the manual, it didn't specify which one so I assumed they were all equally good). After the first one didn't work I tried the second one, and having nothing to suggest that the third would be any idfferent I didn't bother trying it. When I finally tried it out of desperation today, it worked. So yay, computer works, boo, I'm a foolish fool.