Xiaomi Mix 2 Not Charging, DONE !!!

Xiaomi Mix 2 Not Charging

★ = ★ = ★ Successful Analysis Completed With Combinett ★ = ★ = ★

• Story: A middle school student brought repair mix 2 and did not charging, saying that it could not be charging after changing the assembly connector charging.
• Maintenance Analysis: It may be burnt out, because the original charging small board has components such as a protective tube, which are not assembled. Change the original tail first
  

Try to insert a small board, But not effect at all.

• Repair process:

1. Replace the original connector charging, the test still can not charging.
   
2. Plug in the data cable and test the test point TP1305 of the motherboard for the 5V that is inserted in the tail. The test result has 5V.

Explanation The path of the connector charging to the motherboard is normal.

3. Then push the charging circuit upwards through the tail plug connector J1301 on the motherboard.

Open COMBINETT , Search related charging part:

• USB_CC1
  
  
• USB_CC2
  
  
• USB3_HS_DP
  
  
• USB3_HS_DM on J1301

Then these four lines all lead to U600 which is the power supply pmi8998 under the CPU on the back of the motherboard!

Explained that pmi8998 is not only a secondary power supply, but also responsible for charging management.
The point to be explained here is that, like Xiaomi 6, mix 2 uses two-way charging and has a fast charging chip.
U603 cooperates with U600 for fast charging.

4. After analyzing the charging principle, directly change pmi8998

Be careful to cut the CPU right
The shield below, replace with a new pmi8998. After replacing it, measure the surrounding capacitance for short circuit

5. Start the test and charge, O

Attached Images

• mix2.jpg (45.3 KB)
• MI3.jpg (233.3 KB)
• MI4.jpg (234.8 KB)
• mix5.jpg (53.0 KB)
• mix6.jpg (368.3 KB)
• mix7.jpg (223.1 KB)