Pull the board out for testing so you can get to the top and bottom. Fets are 3 legged with the Source and Drain being the output side, and the Gate being the input. Run a quick continuity check on the 3 legs and anything that beeps with the continuity checker is bad. Jumper gate and drain together to the Red probe....see if the black probe on the Source turns on and stays on even when you remove the jumper from the gate. When you disconnect the Drain or the Source....then it should open up again.
That's the general operation of how those FETS get tested.
Leave the Fets in the board during testing.
Copper traces....Power and Current are on the thick ones. The super thin ones are always signal. You check the Thick ones against the thick ones rather quickly, because if there is a short...that's the fastest way to find out. Then you hook your Red probe to each thick trace if you find a short, and slide across the thin ones to see if there is a short on the main power to data/signal lines. That's about the only way to test them.
Then you got to hope you can get the parts with the markings on the body of the parts. That's.....well I'm not going to call it Mission Impossible, but I am going to call it Mission Gee why did I waste all that time testing it when I can get the whole darn shooting match for this price?
Sorry, Mission Impossible was on last night, and I usually start researching parts first then decide if board or parts are the correct choice before troubleshooting. Parts are NOT easy to locate. Boards are easier.
But you should be able to check all Fets and check to see if the ICs are shorted by the time the opening theme is done --
So it doesn't hurt to check them real quick then research afterwards.