Lenovo y7000 notebook no booting repair

Machine model: Lenovo y7000

Mainboard version number: fy510 nm-b961 Rev: 1.0

Fault phenomenon: notebook no booting

Maintenance process:

Previously repaired Lenovo y7000 notebook, the fault is the notebook no booting, not out of the CPU VCC, is this model of common failing, mostly caused by the abnormal resistance of 47 pin of VCC chip mp2949, the fault is the same as replacing 2m resistor.Vccsa VCC has come out and the current is 0.6. Except vcccpucore and vccgfxcore, other VCC are normal.Replace VCC chip mp2949 fault is the same.

Check condition PCH_PWROK,SYS_PWROK,H_CPUPWRGD,CPU_Pltrst ා is normal, basically all the conditions required by CPU VCC are met, but VCC is not produced.

Check the place where the mainboard has been repaired. The CPU model of this machine is i7-8750h. Replace the i5-8300h CPU. If the CPU is replaced, the fault is the same.

Lenovo y7000 notebook no booting repair Figure 1.
There is still no CPU VCC. The opening of this machine chip is given by EC. When EC is damaged, it will not cause CPU VCC.

Lenovo y7000 notebook no booting repair Figure 2.
Replace EC, but CPU VCC still doesn’t work.

Lenovo y7000 notebook no booting repair Figure 3.

Lenovo y7000 notebook no booting repair Figure 4.

According to the drawings, the measurement found that the south bridge was damaged, and the return signal from the south bridge to the CPU was not processed, so VCC did not come out. Replace the south bridge and VCC came out.