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| Samsung Galaxy A53 5G Network issue | |
|---|---|
| Device | |
| Affects part(s) | |
| Needs equipment | |
| Difficulty | |
| Type | |
Problem description
In this condition, your phone experiences severe network issues. You may notice one or more of the following:
- No network service.
- Only emergency calls are possible.
- Complete inability to make or receive calls.
Symptoms
- The phone continuously switches between "Emergency Calls Only" and "No Service."
- Sometimes signal bars appear, but they are only for emergency calls.
- Occasionally, a blocked or crossed-out icon replaces the signal bars.
- Flight Mode can be toggled normally (the button is not greyed out or stuck).
- You can manually switch between different network modes (2G, 3G, 4G, 5G), but the problem remains.
Root Cause
The issue is usually caused by a malfunctioning or shorted APT IC located near the CPU. When the APT IC fails or operates inconsistently, it disrupts the network power supply (VPA_APT), leading to unstable or no network service.
Solution
There are 2 ways to fix this issue:
- Replace the ic.
- Bypass the ic but not by removing it
Diagnostic Steps
- Check for Shorts:
- Inspect the area around the network-related ICs for short circuits (see the image)
- Measure VPA_APT Output:
- Probe the VPA_APT coil output (in the picture)
- The expected voltage should be in the range of 2.0V to 4.2V (depending on battery voltage)
- If the reading is 0.00V or fluctuates continuously, proceed to repair steps
Repair Steps
Solution 1: Replace the APT IC
- Remove the shield covering the IC.
- Desolder and remove the faulty APT IC(shown in the picture)
- Inspect the PCB pads for any damage.
- If pads are intact, proceed.
- Reball the replacement APT IC using 183°C (medium-temp solder paste).
- Install and solder the new IC onto the board.
- Verify the repair by checking network functionality.
Solution 2: Bypass the APT IC (Jumper Method)
- Locate the VPH_PWR point on the motherboard (shown in the picture)
- If the APT IC is burnt, first remove the VPA_APT boost coil.
- Create a jumper wire connecting VPH_PWR to the VPA_APT output (refer to image for exact points).
- Apply solder mask to secure the jumper and prevent shorts.
- Test the phone’s network functionality.