There is a sound but no picture in to the screen and there is horizontal line

Tv have a Horizontal IC out is dead or cold soldering.Make a fist with ur hand,bang on the tv frame bazel a couples of times.If the hoizontal line flashes back to normal screen?Tv have cold soldering around horizotal IC area.U have a soldering iron tool and a roll of solders,know how to do basic soldering?Take the back of the plastic screw driver tap around for cold soldering area.Resoldering those area.No horizontal tv screen flashes back the IC out is dead,require replacing another horizontal IC output.