They are mosfets and do not have have collector or emitter.
It looks like your probing Drain to Source and one way should be nesr open and the other
you should see the substrate diode.
IF the fets are shorted then will show near zero ohms Source to Drain.
When you turn it on how many amps does it require?
What is the Voltage at the power supply after you turn it on?
If you disconnect the BROWN wire (power to the output transistors) does it power up?