Help identifying this power MOSFET
AOU438L from Alpha Omega semiconductor.

http://www.alldatasheet.com/datasheet-pdf/pdf/135752/AOSMD/AOU438L.html

VDS (V) = 30V
ID = 85A (VGS = 10V)
RDS(ON) &lt; 4.5mΩ (VGS = 10V)
RDS(ON) &lt; 6.5mΩ (VGS = 4.5V)


Datasheet mentions it is designed for low-side switching in CPU power conversion.  So you could probably scavenge a suitable replacement from an old motherboard.