The loud noise produced by the television when it is first turned on is part of the televisions normal degauss cycle. This noise is normal.
This degauss cycle eliminates any static build up around the picture tube (CRT) and helps the television reproduce uniform colors over the entire picture tube.
DEGAUSS: The earth's natural magnetism can cause unwanted magnetic fields to build up inside a monitor or television, causing a loss of color purity. Degaussing removes these stray fields. For this reason, Sony color televisions have an automatic degauss feature.
Since the Sony CRT has aperture grill for the best picture the degauss can cause a loud ping sound when first turned on. This is normal and is not harrmful to the TV.