Hello, everyone!
Today, I'd like to share a case with you.
Product Model: EchoLife EG8145V5
Problem Description
The user reported that the 5G Wi-Fi of two EG8145V5 was weak. He tested the Wi-Fi signal of two ONTs (1#EG8145V5 and 2#EG8145V5).
Test environment: 1#EG8145V5 and 2#EG8145V5 are adjacent to each other, and the distance between the Wi-Fi clients is 2 m.
5G Wi-Fi test: After 5G Wi-Fi is connected, the Wi-Fi signal is unbalanced, and the subsequent interruption occurs.
2.4 GHz Wi-Fi test: The connection and signal quality are normal.
Problem Analysis
1. Check whether the transmit power level of 5G Wi-Fi is 100%.
2. Check the 5G Wi-Fi connection, and STAs are connected. This means the 5G Wi-Fi connection is normal and the 5G FEM is working normally.
3. The signal strength refers to the strength of the received STA. If the 5G FEM issue occurs, the signal strength will be worse.
4. Use the test tool to test the signal strength at a distance of 20 cm. The test signal strength is –80 dB.
We sent the ONT to the maintenance office for fault analysis.
Check the 1# EG8145V5 and 2# EG8145V5 appearance, they are normal.
Power on 1# EG8145V5 and 2# EG8145V5, Check the 5G Wi-Fi signal, they are weak.
Remove the shells of two EG8145V5 and check the internal boards.
The results are as follows:
1# EG8145V5: The appearance of the internal shell and board are normal.
2# EG8145V5: Abnormal material on the board around 5G FEM chip.
Further analysis of the 1# EG8145V5：
Measure the 5G Wi-Fi circuit and find that the power source circuit is abnormal. Specifically, the power impedance is abnormal. It was confirmed that the power chip was faulty. After the power chip was replaced, the problem was resolved. Based on the preceding analysis, we determined that the chip was EOS(electrical ove0rstress) damaged.
Further analysis of the 2# EG8145V5：
Abnormal material was found around the 5G FEM chip, after checking the wifi circuit function fem cannot work normally (to be specific 5V power impedance is abnormal). The possible root cause for this problem is abnormal material damage 5G FEM chip and then 5G Wi-Fi signal weakening.
Root Cause
Possible root causes of chip out-of-service (electrical overstress) damage:
The peak voltage of the electronic power supply is unstable.
Poor quality power strip.
Adapter error.
Solution Description
It was determined that the 1# EG8145V5 chip was damaged due to EOS (electrical overstress). The fault is rectified after the power chip is replaced.
The abnormal material of 2# EG8145V5 damaged the 5G FEM chip, which weakened the signal. It is recommended that the 2# EG8145V5 be replaced.
Welcome to leave a message below.
We study together.
Thank you!
