WARNING BEEP- DELL LAPTOP INSPIRON

I have a laptop DELL Inspiron, with i3 processor (n series).
Yesterday, it suddenly started giving a long beep, without affecting any other program. Meaning everything was working fine except the continuous sound.
I tried everything advised to me by the dell experts, like taking out the RAM (I have 2 rams of 1 GB each, and took out the RAMS one by one), the battery, the power supply and so on, but the beep is still present. Eventually I had to disable the sound card.
By the way I have Realtek High definition audio card. I checked the driver from the dell website, as well as from the Relate, and can confirm that I have the latest drivers.
I am really worried that what could be wrong with my system. Please note, the system has passed its warranty period, and if I give it to any technician, I have to pay. Can it be avoided? Has anybody else experienced this issue?
RU
