Only if it's when using external equipment such as decoders, dvd, video recorders. When you could check for loose connecting cables.
Otherwise, you'd need an engineer.
Common causes for black raster with sound, faulty video processor (IC is usually marked VDP#####) in Panasonics, or faulty frame output IC. can cause screen blanking to activate. Then you'd need an engineer.
Cobweb, October 2005