Google Pixel 9 Pro: 5G Loss After Update - Solution

⚠️ SAFETY WARNING / FIRE RISK. This device contains lithium batteries. Improper puncturing or bending during disassembly can cause explosions or flames. The intervention requires precision and the assistance of a specialized technician is recommended. ReeFix provides this diagnosis EXCLUSIVELY for educational and informational purposes.

QUICK TEST

This section allows you to perform preliminary checks on your Google Pixel 9 Pro to identify the nature of the 5G problem post-update, useful for an initial assessment.

1. Forced Device Restart: Press and hold the power button for about 30 seconds until it fully restarts. This can resolve temporary software conflicts or system freezes.
   • Key signal: If 5G returns, the problem was a minor software glitch.
2. Check Baseband Version: Go to Settings > About phone > Baseband version.
   • Indicator: If the version is "Unknown" or completely absent, this suggests severe modem firmware corruption (High probability).
   • Counter-example: If the version is present and corresponds to a numerical value, it is more likely a configuration or driver issue, not a total corruption of the radio partition.
3. SIM Card Test: Insert your SIM into another compatible and working 5G smartphone.
   • Indicator: If 5G works on the other phone, your SIM is intact. If it doesn't work, the SIM might be damaged or obsolete (Low probability, about 5%).
4. Reset Network Settings: Navigate to Settings > System > Reset options > Reset Wi-Fi, mobile & Bluetooth. This operation does not delete your personal data.
   • Why: Resets network profiles and APNs (Access Point Names) that may have been corrupted or rendered incompatible by the update.
   • Often happens when: An update introduces new configurations that the old APN profile does not handle correctly, causing 5G disconnections.

DECISION FORK

Based on the quick test results, you can orient yourself towards the most appropriate solution for your Google Pixel 9 Pro.

Scenario A: Software-Related Problem (85% Probability)

• If the forced restart, SIM test, or network settings reset partially or totally restored 5G connectivity, the cause is likely related to:
• Modem firmware / Radio Partition Corruption (65%): The update incorrectly wrote the radio.img partition, which manages the Exynos 5400 modem.
• Incompatibility or corruption of Carrier Policy files (20%): Network parameters specific to your mobile operator were not migrated correctly during the update.
• Decision: Consult a specialized technician.
• Why: Resolution requires a clean "flashing" of the factory firmware via Android Flash Tool, an operation that overwrites all partitions, including the modem's. This procedure, although software-based, is technical and can void the warranty if not performed correctly.
• Estimated cost: Labor for this advanced software diagnosis and restoration is generally between €40 and €80. No costs for spare parts are expected.

Scenario B: Possible Underlying Hardware Damage (10% Probability)

• If the baseband version is "Unknown" or absent after the quick test, or the device exhibits abnormal overheating (in the upper motherboard area) with a total and persistent signal loss (even LTE), the cause could be:
• Desoldering or physical damage to RF chips due to thermal stress (10%): The update, with its workload, generated a heat spike that could have damaged BGA solders or already fragile RF components.
• Decision: Consult a specialized technician for an in-depth hardware diagnosis.
• Why: Requires opening the device in an ESD-protected environment, microscopic inspection of the Exynos 5400 modem's BGA solders, and verification of RF power lines and antenna connectors.
• Estimated cost: If the hardware damage is repairable (e.g., antenna connector, reballing of a minor chip), the repair could cost between €80 and €150. If motherboard replacement is necessary (a rare but possible event for extensive damage), the cost can range from €150 to €250 for the part, plus labor.
  • Consideration: In case of motherboard replacement, carefully evaluate the total cost against the device's residual value; replacing the Pixel 9 Pro might be more cost-effective.

Scenario C: Minor or External Causes (5% Probability)

• If none of the previous scenarios align with your symptoms and you have already tested the SIM, consider:
• Degraded SIM card: Scratched gold contacts or general wear.
• Temporary mobile operator issue: Service interruptions in your area.
• Decision: Try a new SIM card or contact your operator directly to check coverage and network status. If the problem persists, the cause likely falls into Scenario A or B.

DIAGNOSIS CONFIRMED

The loss of 5G connectivity on the Google Pixel 9 Pro following an update is, in most cases, a software-resolvable issue, but it requires targeted intervention and specific skills to avoid further complications.

Preliminary Technical Report:

The described phenomenon, namely the loss of 5G network connection capability after an Over-The-Air (OTA) update, indicates with high probability (85%) a software problem. The Tensor G4 SoC, with its Exynos 5400 modem, relies on precise synchronization between the Android firmware and the radio partition. An unsuccessful update can corrupt this partition or operator-specific configuration files (Carrier Policies), preventing the modem from correctly negotiating 5G protocols. A typical error in these cases is a misalignment that leaves connectivity limited to 4G/LTE networks.

Output for the Specialized Technician:

"The Google Pixel 9 Pro experienced a loss of 5G connectivity immediately after an OTA update. LTE/4G connectivity is partially or totally functional, or the baseband version is 'Unknown'. An in-depth software diagnosis is required, starting with an attempt at a clean flash of the factory image via Android Flash Tool, ensuring the radio partition is rewritten. Verify the integrity of carrier configuration files and any corruption of EFS/NVRAM partitions. If the problem persists, proceed with a targeted hardware verification, microscopically inspecting the BGA solders of the Exynos 5400 modem and the coaxial antenna connectors, with particular attention to signs of thermal stress or micro-fractures."

Diagnosis Tools for the Technician:

For a professional intervention, a qualified technical laboratory would use:

• Anker PowerLine USB-C data cable for high-speed to ensure maximum stability during firmware flashing operations.

When "unknown baseband" appears on the Pixel 9 Pro, the phone completely loses the ability to read the SIM and connect to any network signal, not just 5G. This happens because the operating system can no longer communicate with the Exynos 5400 modem due to corrupted partitions.