David, may be there is more to this repair than just to replace the parts. Anyhow to answer your question
1) Reference designator U5410 is a INA214 in a SC70 and is a TI Voltage Out Current Shunt Monitor
2) Reference designator U5400 is a INA213 in a SC70 and is a TI Voltage Out Current Shunt Monitor
The INA213 and INA214 are voltage-output, current-shunt monitors that can sense drops across shunts at common-mode voltages from –0.3 V to 26 V, independent of the supply voltage.
3) Reference designator Q4262 is a BSS8402DW in a SOT-363 package and it is a COMPLEMENTARY PAIR ENHANCEMENT MODE MOSFET available at Digikey.com.