Well, you need more than good tools and a soldering iron. You also need an Oscilliscope with probes, Hi-Voltage CRT tester, DVM and a TV RF generator to start. The first thing I would do is to verify that all the voltages in the low voltage supply are within specs. Don't mess with the Horizontal voltages unless you know where to probe. A schematic would definitely help. Some TV's have the voltage levels print screened on the main board by the terminals. Have you tried disconnecting the Antenna, cable or satellite signal from the RF input and see if you get just plain snow when you first turn it ON? Bypass the tuner if you have RCA receptecles for video inputs and check it out that way. Too many T/S procedures to list here. Just find a good reputable TV repair person.