Address
304 North Cardinal
St. Dorchester Center, MA 02124
Work Hours
Monday to Friday: 7AM - 7PM
Weekend: 10AM - 5PM
Model: Shenzhou Ares Z10-CU7PF New 10th Generation U
Malfunction: The screen does not display.
Maintenance process: the second repair machine board sent by my colleague was checked, the bridge was replaced, the CPU power supply was replaced, and the EC was also replaced. Measure the power supply resistance of the main board quickly, and no problem is found. Then, it depends on the power supply, and the trigger current is about 0.3.
This is obviously a lack of voltage on the main board. The CPU power supply is 0V, and the CPU power supply chip that has been moved is reprocessed again, but there is still no CPU power supply. Therefore, other power supply voltages on the board are measured, and the memory voltage is 1.23V V.
The VCCIO voltage is normal (0.98V).
The voltage of VCCSA is normal (1.24V).
After repeated voltage measurement, no abnormality was found except CPU voltage. Next, measure the clock signal, determine whether the bridge is working or not, and send out the clock. Measure the clock signal of the wireless network card interface (0.54V), and the clock sends out normally.
Power supply and clock are measured. Next, PG (good signal of power supply) needs to be measured. The measured PG of VCCSA is normal (1.06V,).
The two pgs of CPU are also about 1V.
Since all the bridges have been able to send out CPUPG, it means that there is no problem with the work on the other side of the bridge, and the CPU can’t supply power. It’s probably that the CPU is so bad that it can’t send out SVID, resulting in voltage failure.
You need to change the CPU for testing, find a material board, remove a CPU of the same model, and plant tin.
Put the failed motherboard in BGA repair station for heating, remove the CPU, and install the tin-implanted CPU on the motherboard. After the motherboard cools down, the startup current of the adjustable power supply jumps normally. Install the motherboard into the machine for startup test, and it can light up normally. The maintenance is over here!
