I need some help 'cause Italian NG or formus doesn't help me much.. Many years ago i've much probably caused a damage to a Daewoo DTG2997 crt Tv (chassis C1000) connnecting a computer to it, one 12v may have been connected for error to the ground and came in to the tv through the RCA video/audio cable's ground, now AV inputs, apart antenna, doesn't work well, if i put a RGB signal through the SCART AV cable the image is visible but without any sync, if i put a videocomposite signal the screen is empty/dark (dark grey), so i don't understand why antenna video signal is displayed well and other inputs not.. (i'm not an expert). theese are the relevant pages of schematics:
Many thanks in advance.