Hi there!
First of all, I recommend to replace the AV cable. Most likely this one is faulty causing the issue you are facing.
Here you can get a new cable: https://www.ebay.com/itm/404053371692?itmmeta=01JGKB30G4JZMVQ4ZJEJDDQD0J&hash=item5e13752b2c:g:qYEAAOSwV75gt-I8&itmprp=enc%3AAQAJAAAA4Mxmj%2BiGvOveHXEBClPb29ihHydyHVdqwqaAUKlAUMJicuQjKX3z%2FTjmbLtGSCCUAgx%2B7c2iH0ySDoYi2BTzRbOb6o7iEMh8ZhGf8fUbcWzegXj2xLtG%2BMjJvacyHKbzkBK3rZ9jzBkktawhnIbHiXKNEVmSFbCnh78PAZCellOlccbLMcebBVbAo2Ev7Nw%2FxjZ4%2F0d5fsCKX7OpHhiHiie%2FcqGrHH%2BxrJpv3s4HaE9nRUIh%2BOqYm5FMuOEJOGTb7uBPKhcB3uH%2BvpFn%2F80vK%2BlGogerV0SMWwPpzA%2FhTCMp%7Ctkp%3ABk9SR5KIjOuEZQ
Easy and cheap to replace it :)!