Ian Steadman thought the most likely cable faults to affect LCDTv's were :
1) FAST BLANKING : Some users have said a 220 ohm (instead of the 75 ohm he originally recommend) should be used on SCART pin 16.
2) COMPOSITE_SYNC : voltages, the Amiga voltage range for that pin is TTL which is not the same range as the SCART voltage for that pin. Adding a 330 ohm resistor on SCART pin 20 will fix this.
3) No AC coupling. Adding 220uF capacitors in series on the RGB lines (SCART pins 7, 11 and 15) may help