As far as i can see (and understand) the schematics:
… the U5 (AP7361C) and U6 (TLV70033) regulators are directly connected to the power switch. Both are responsible for driving the video A/D converter (TVP7002PZP/U1) and the later one for driving the video amplifier too. So hopefully just U6 or (at worst) U5 and U6 were damaged and nothing else. Cause they are not only cheap to buy but easy to replace too.