FET (Field Effect Transistor)

MOSFET (metal-oxide semiconductor field-effect transistor)

J FET (Junction field-effect transistor)

used in : 

1. cpu power section 
2. ram power section
3. mother board power section
4. 
   

multimeter  checking process:

OK: one side high value and other side low value or one side value and other side Nothing

Damage:one side value and other side Buzzer or Both side buzzer .

Compare to ground : ground to emitter buzzer (NPN) or both side to emitter high value or both side to collector low value