Mention of the day was a good news.
After a long time of trial and error and discovery atlast I surpassed tricks to make my front panel of CPU working. Now I can hear and use microphone directly from front panel through my Headset by Zebronics without the LG Desktop Speakers powered on. So I powered them off, first time from computer's arrival and now fully depending on 2nd Audio Output through front panel by Headset. But Speakers at my disposal, anytime I can turn them on, with full volume music whenever required.