The component you circled is L7600 in the schematic, and like Dan said in his comment it's part of the power logic. You said you replaced the logic board. With the replacement board installed and everything connected, do you get any signs of life from the system other than a warm L7600 and a warm CPU/GPU? Does the CAPS lock light turn on on the keyboard? Do you hear a chime? Do the fans spin up at all? You should also try the replacement logic board in different install configurations to rule out certain components causing issues—for example, you could try powering on with the display disconnected, or the trackpad disconnected, or the battery disconnected, etc., to see if you get different behavior or if another component could be failing. It's very common with liquid damage for multiple components to be damaged—make sure to check the USB-C boards and their pins for corrosion as well. Good luck!