Shenzhou elegant HP640 notebook boot does not respond repair

Machine model: Shenzhou elegant HP640 notebook

Main board version number: DAOQL6MB8FO REV:F

Malfunction: The laptop is not responding when it is turned on.
Maintenance process:
Received a Shenzhou Elegant HP640 laptop, but memory, current has maintained 0.85 mA, and the replacement memory is invalid. Disassemble.

Shenzhou elegant HP640 notebook boot does not respond repair Figure 1.
Look at the back of the motherboard and find that the graphics card has been soldered or changed. First, the Repeat welding graphics card is still the same, then the Repeat welding North Bridge, the test current run code, 0.57-0.85-0.89-0.98-1.25 is on, and the same problem still exists when the motherboard is cooled and tested again.

Shenzhou elegant HP640 notebook boot does not respond repair Figure 2.
BGA Rework Station Reballing, Beiqiao chip bead arrangement [0.5], the current is directly 0.65mA after replacement.

Shenzhou elegant HP640 notebook boot does not respond repair Figure 3.

Shenzhou elegant HP640 notebook boot does not respond repair Figure 4.
0.65mA should be that the CPU didn’t come up. After inspection, it was found that the two Capacitor behind the CPU were broken. Replace two 330U Capacitor, power-on test, current up to 1.26, shut down and connect the screen,Capacitor.