Dell inspiron 15 7559 Notebook no power on can't be opened for repair

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair.

Machine model: Dell 15 7559

Main board version number: daam9amb8d0erev: d

Malfunction: Notebook no power on can’t be turned on.

Maintenance process:

Got one. Dell inspiron 15 7559The game book and notebook no power on can’t be turned on.

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair Figure 1.
Disassemble the back cover, without water damage.

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair Figure 2.
Dismantling the machine, it was found that the position of two P tubes in the place where the power supply 19V went in was burnt black, and the back was also black, especially the PR61 2R2 patch resistor was cracked.

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair Figure 3.

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair Figure 4.
Remove the motherboard,SMD REWORK STATION blows PQ40 and PQ41 MOSFET, and finds that PQ40 MOSFET even the bottom MOSFET is worn.
It still won’t work to replace two MOSFET,Cleaning solvent is cleaned,Jump wire is connected with 5678 of two MOSFET, and one line of MOSFET connected to 19V power interface passes through.

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair Figure 5.

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair Figure 6.

123 pin is completely useless, so even the battery can’t be used in the past.
Power-on test, measuring 12 pin 19V of standby chip PU16 has passed.

Dell inspiron 15 7559 Notebook no power on can’t be opened for repair Figure 7.

Press Switch line energy switch, indicating that it has been repaired, installed and tested, and Normally booting up is turned on, that is, the battery can’t be used.