Elegance HP640 notebook computer in Shenzhou but memory repair

Elegance HP640 notebook computer in Shenzhou but memory repair

0.65mA should be that the CPU didn’t come up. After checking, it was found that the two capacitors behind the CPU were broken. Replace two 330U capacitors, make sure that there is no error in power-on test, and the current goes up to 1.26. Turn off the machine, connect the screen, and turn on the machine.

Machine model: shenzhou elegant HP640 notebook

Main board version number: DAOQL6MB8FO REV:F

Failure: The laptop has no memory.

Maintenance process:

I received a Shenzhou elegant HP640 notebook computer, but the memory and current kept at 0.85 mA, so the replacement of the memory was invalid.

Elegance HP640 laptop in Shenzhou but memory maintenance Figure 1

Disassemble the machine, check the back of the motherboard, and find that the video card has been welded or changed. First, weld the video card, and then weld the North Bridge. Test the current running code, and it lights up at 0.57-0.85-0.89-0.98-1.25. Wait for the motherboard to cool down, and then test again, and the same problem remains. Replanting on BGA.

Elegant shenzhou HP640 notebook computer but memory maintenance figure 2

North bridge chip [0.5], after replacement, the current is directly 0.65mA.

Elegant shenzhou HP640 notebook computer but memory maintenance figure 3

Elegant shenzhou HP640 notebook computer but memory maintenance fig. 4

0.65mA should be that the CPU didn’t come up. After checking, it was found that the two capacitors behind the CPU were broken. Replace two 330U capacitors, make sure that there is no error in power-on test, and the current goes up to 1.26. Turn off the machine, connect the screen, and turn on the machine.

Elegance HP640 laptop in Shenzhou but memory maintenance Figure 5