Modern flat screens are actually far more simple than the TVs of yore; that actually makes them more difficult to repair. You will typically have a power supply

Modern flat screens are actually far more simple than the TVs of yore; that actually makes them more difficult to repair. You will typically have a power supply (and if not an LED backlight, then a high voltage one as well) and a "T-Con" board, which usually has one honking big SoC on it which is both Vendor and TV specific. There isn't that much to repair aside from the power supply, and honestly you don't really need a schematic for that to repair it.