How To Use Secret Codes On Oppo A9 2020 Upd [Fully Tested]

Code: *#8778#

This code prompts a total factory reset (wipe all data, logs, settings). Unlike the Settings menu, this does not ask for a password if the screen is unlocked. Back up your data before using this.

Here are the most reliable codes tested on the OPPO A9 2020 with CPH1937, CPH1939, and CPH1941 models.

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Accessing secret codes on your OPPO A9 2020 (CPH1937/CPH1931) allows you to perform hardware diagnostics, check software versions, and view battery health without navigating complex settings. 🛠️ Core Diagnostic Codes *#899#

Full Engineer Mode / After-Sales Tool. Tests LCD, cameras, sensors, and GPS. *#800#

Feedback Menu. Used to report system lags, battery drain, or GPS issues. *#6776#

Software Information. Displays ColorOS version, Android version, and kernel details. *#06#

IMEI Check. Displays your device's unique identification numbers. *#*#4636#*#*

Phone Information. Detailed battery stats, Wi-Fi status, and network usage. 📝 Step-by-Step Guide Open Dialer: Tap the Phone app icon on your home screen. Enter Code: Carefully type the sequence (e.g., *#899#).

Automatic Execution: Most codes on the A9 2020 trigger the menu automatically once the final # is pressed. how to use secret codes on oppo a9 2020 upd

Select Test: If using *#899#, choose Manual Test to check specific components like the proximity sensor or vibration motor. 🔍 Key Updated Codes (2024-2026)

Hardware Revision (*#888#): Quickly identifies your mainboard (PCB) serial number and hardware version.

FCM Diagnostics (*#*#426#*#*): Checks Google Play Services connection events and real-time status.

Calendar Info (*#*#225#*#*): Shows the number of saved events and technical calendar metadata.

SAR Level (*#07#): Displays the specific absorption rate (radiation level) for your device. ⚠️ Important Safety Tips

Avoid Random Codes: Some codes found online can trigger a factory reset (e.g., *#8778#) and erase all your data immediately.

Settings Caution: Do not change parameters in Engineer Mode unless you are a trained technician, as it can affect network connectivity or sensor calibration.

Exit Normally: Always use the "Back" button or "Exit" option to leave a secret menu rather than forcing a restart.

Note on Developer Options: If you need deeper system access, go to Settings > About Phone and tap Version seven times to enable "Developer Options" under Additional Settings. If you're having a specific issue, tell me:

What problem are you trying to fix? (e.g., screen lag, battery drain, or sensor issues) What ColorOS version are you currently on? I can guide you to the exact test or setting you need. Codes for OPPO A9 2020 - HardReset.info Code: *#8778# This code prompts a total factory

To use secret codes on your OPPO A9 2020 Go to product viewer dialog for this item.

(updated for April 2026), open your phone’s default Dialer/Phone app and type the specific numeric string exactly as shown. Most codes will execute automatically as soon as you press the last character (usually #) without needing to press the call button. Essential Diagnostic Codes

These codes allow you to check hardware health and system information:

*#899# – Engineer Mode / AfterSale Page: The primary diagnostic menu used by technicians to test the screen, audio, camera, and sensors.

*#06# – IMEI Check: Displays your device’s unique international mobile equipment identity, which is essential for warranty or lost-phone tracking.

*#6776# – Software Info: Detailed view of your Android version, ColorOS build, kernel, and branch details.

*#888# – Hardware Revision: Displays your PCB (mainboard) serial number and hardware version.

*#07# – SAR Level: Shows the Specific Absorption Rate (radiation level) for your device. Advanced Testing & Network Codes

Use these for deeper system insights or troubleshooting connection issues:

*#800# – Feedback Menu: Used to log system performance or report bugs like GPS lag directly to OPPO. Would you like a version formatted as a

*#*#4636#*#* – Phone Stats: Shows detailed information about battery health, usage statistics, and Wi-Fi/network signal strength.

*#36446337# – Manual Hardware Test: An alternative engineering menu for specific manual component tests.

*#*#426#*#* – FCM Diagnostics: Provides information on Google Play Services connection events.

How to Run a Full Diagnostic Test on an Oppo Smartphone: All Methods

Here’s a clear, helpful, and safe guide on how to use secret codes (also known as USSD codes or engineering codes) on the Oppo A9 2020, especially after a software update (ColorOS 11 or 12 based on Android 10/11).

The OPPO A9 2020 is a powerful mid-range smartphone known for its massive battery, quad-camera setup, and smooth ColorOS interface. However, like most Android devices, it hides a treasure trove of diagnostic tools, test menus, and engineering screens behind a series of secret codes (also known as USSD codes or MMI codes).

If you have searched for "how to use secret codes on oppo a9 2020 upd", you are likely looking for the latest, working codes to test your hardware, access advanced settings, or recover information. This updated guide for 2025-2026 provides a complete, step-by-step walkthrough.

⚠️ Warning: Secret codes give access to system-level tests. Do not change values in "Engineering Mode" or "Device Test" unless you know exactly what you are doing. Incorrect settings can affect your phone's performance.

After typing the last #, the screen will switch to a test menu or display information.