HP 14s-cf0002tu notebook water damage no booting repair

HP 14s-cf0002tu notebook water damage no booting, change to sy8208b,VCC is normal.

HP 14s-cf0002tu notebook water damage no booting repair

Machine model: HP 14s-cf0002tu
Board No.: 6050a2993001-mb-a01 (A1)
Fault phenomenon: notebook water damage no booting, power on indicator light is not on
Maintenance process:

HP 14s-cf0002tu notebook water damage no booting, power on indicator light is not on.

After dismantling the machine, it was found that a little water was fed into the 3V stand-by place, and the power was turned on after the treatment. There was no 3V in 5V, only 0.5V in 3V LDO, and no Short circuit in the later stage Diode value is normal.After disconnecting ldo3 test point, ldo3 can output 3.3V, chip screen printing L8 =, model rt6265b.
惠普14s-cf0002TU笔记本进水不开机维修 图1

HP 14s-cf0002tu notebook water damage no booting repair Figure 1.
It was found that 6 pin en also had 0.5V power supply, which was abnormal. After disconnection, ldo3 output was normal, and en sent by EC also had 3V. This indicates that the problem lies in this. The chip and peripheral small parts are replaced, and the result is the same.Disconnect 6 pin en, disconnect the standby 3.3 test point,DC power supply add a 3.3 retest point back end,Connect the power supply source can be turned on.
惠普14s-cf0002TU笔记本进水不开机维修 图2

HP 14s-cf0002tu notebook water damage no booting repair Figure 2.
Change to sy8208b,VCC is normal.
惠普14s-cf0002TU笔记本进水不开机维修 图3

HP 14s-cf0002tu notebook water damage no booting repair Figure 3.
Power on, power on test,Normally booting up, troubleshooting, maintenance is over.
惠普14s-cf0002TU笔记本进水不开机维修 图4

HP 14s-cf0002tu notebook water damage no booting repair Figure4.