Your Hard Drive is the likely cause of the Gong ( church bell ) sound. I heard drives before make a sound like that, just not as loud as a church bell gong and it was the arm in the drive slamming and the platters in the drive resonating the sound to make a bell like sound.
Do you have the media to install clean or repair installation for this computer?
Do you happen to have a spare hard drive available to swap out the drive, and install clean to a different hard drive?