Now this system was having a problem due to which only one speaker(2.1) was producing sound.The speaker jack was connected to the sound card.
So I decided to test the speakers with the onboard sound and removed the sound card from the system after detaching all cables from the cabinet.Later after reconnecting the cables, the system would simply not boot.The green light on the front panel was glowing and the CPU fan was rotating but the monitor was completely blank and there was no beeps or sounds of Windows booting.
I checked the cabling several times in all possible combinations but to no avail.
Another thing, after powering on the UPS, the green light glows and the CPU fan rotates automatically without the need to press the power button.
Needing help, desperately...