I've a VGA monitor which I could connect and tryDo you have another monitor or TV you can try it with.
I've connected all the connectors, motherboard 24 pin and CPU 6 pinAlso, are you 100% certain that all your connectors are all properly connected?
How do I clear CMOS?Try a Clear CMOS.
I've HDD and DVD ROM connected, I remove the SATA cable and power cables from them?Remove all drives (don't need them to get the BIOS up)
I've a DVI monitor and a old VGA monitor, connected both to the motherboard without any adapterIf you are trying to connect a VGA monitor to a DVI-D connector using a converter (on the board and maybe one on the GFX card) then you wont get a display.
I'll give that a goTry one stick of RAM in different slots.
How do I clear CMOS?