How to go to the engineering menu on Xiaomi Redmi Note 8T: hidden codes and secure settings

Why do you need access to the engineering menu on the Redmi Note 8T?

The Engineering Mode on Xiaomi smartphones is a hidden tool that allows you to access low-level hardware and software settings. On the Redmi Note 8T (model M1908C3XG), you can test sensors, calibrate the screen, check the communication modules and even optimize performance through this menu. But why isn't this tool included in the standard settings?

Manufacturers hide the engineering menu for two reasons: first, the wrong changes can lead to unstable device operation or loss of warranty; second, most users simply do not need such deep settings. However, for enthusiasts who want to squeeze the most out of their Redmi Note 8T, this menu becomes a real godsend. Here you can, for example, calibrate the accelerometer for accuracy in games, check the real state of the battery, or even unlock the hidden frequencies of the 4G/5G (if supported by iron).

It's important to understand that the engineering menu is not a magic wand for overclocking a smartphone; it's a professional tool that requires caution. On the Redmi Note 8T, some of the options in the engineering menu are locked at the MIUI firmware level, and changing them may require super-user rights (root).

Official and unofficial ways to enter the engineering menu

There are three main ways to get into Engineer Mode on Redmi Note 8T: through USSD codes, using the Phone app, and through ADB- commands. The first method is the easiest and works on most Xiaomi devices, but can be blocked in some regional firmware. The second and third require additional actions, but give access to advanced features.

Let’s look at each method in more detail, starting with the safest one.

1. Entering through the USSD code (the fastest way)

This is a standard method that works on most Xiaomi smartphones, including the Redmi Note 8T. You don’t need additional programs or root rights – just the phone’s keyboard.

Instructions:

• 📱 Open the Phone app (standard call app).
• 🔢 Enter the code ##4636## or ##3644633## (for hardware testing).
• 🔍 If the code worked, you will see a menu with tabs on Information, Battery, Usage statistics, and more.
• ⚠️ If nothing happens after you enter the code, your firmware blocks this method (see alternative methods below).

Entry via the "Phone" application (alternative method)

If the USSD- codes didn't work, try this method. It's suitable for firmware where standard codes are locked, but requires precise follow-up.

Steps:

1. Open the phone app.
2. Go to the keyboard tab (where you dial the number).
3. Enter the combination: ##4636## (no stars!).
4. Press the call button (green tube).
5. If the menu doesn't open, try entering ##3644633##.

Battery charge of at least 50%|Important data is stored (in case of failure)|Disabled. VPN Proxies (can block access)|Internet connection stability (for the purpose of ADB-method)-->

3. ADB Entry (for power users)

This method is more complicated, but more reliable if the previous ones didn’t work, and requires connecting your smartphone to your computer and installing Android Debug Bridge (ADB).

Step-by-step:

1. Download and install Google’s Platform Tools (includes ADB).
2. On your smartphone, activate Developer Mode: Go to Settings → About Phone. Click 7 times on the MIUI Version until the notification "You're a developer" appears. Return to Settings → Additional → Developer. Enable USB Debugging.

Redmi Note 8T

Open the command prompt (Windows) or terminal (macOS/Linux) in the folder with ADB.

adb devices

If the device appears in the list, enter:

adb shell am start -n com.android.settings/.TestingSettings

⚠️ Warning: If an Activity not found error occurs after you run a command, your firmware doesn't support that method, so you only have the first or second method.

What can you do with the Redmi Note 8T Engineering Menu?

The engineering menu provides access to dozens of options, but not all of them are safe to change. Below we will look at useful features that will not harm the device if used wisely.

Testing of equipment

The Hardware Testing tab (or Device Test) allows you to check the performance of all components of the smartphone:

• 🔋 Battery: Real charge level, temperature, voltage.
• 📶 Network: Signal strength, supported frequencies, SIM-map information.
• 🔊 Audio: Test of speakers, microphone, 3.5mm connector (if any).
• 📱 Sensors: accelerometer, gyroscope, compass, proximity sensor.
• 📸 Camera: Checking the operation of all modules (main, wide-angle, macro).

💡 Helpful tip: If you notice that your smartphone is running out faster, check the Battery tab. This shows the actual battery status, including the number of charging cycles and current capacity. If your Battery Health value is below 80%, it's time to consider replacing the battery.

Network and communication configuration

In the engineering menu, you can optimize the operation of mobile Internet and Wi-Fi.

• 📡 Network selection: Forced switch between 2G/3G/4G (useful if the smartphone is "stuck" on a slow network).
• 🔄 Band Selection: Manually select the frequencies for the best signal (relevant for regions with poor coverage).
• 📶 Signal Strength: Monitoring of signal strength in dBm (norm: from -70 to -100 dBm).

⚠️ Warning: Changing network settings can lead to loss of connection or inability to make calls. If you are not sure about your actions, it is better to return the settings to factory (Restore Default).

Sensor calibration

If you have problems with autorotating the screen, gestures or playing, you can recalibrate the sensors in the engineering menu:

1. Go to Sensors or Sensor Test.
2. Choose an Accelerometer or a Gyroscope.
3. Follow the instructions on the screen (usually put your phone on a flat surface and wait a few seconds).
4. After calibration, restart the device.

🔧 Note: On the Redmi Note 8T, the sensor calibration may reset after the MIUI update. If the problem returns, repeat the procedure.

What can’t you do on the engineering menu?

Not all settings in Engineer Mode are safe to change, and some settings can disrupt your smartphone, cause data loss, or even "bricking" (turning into a brick) and this is something you should not touch:

• 🚫 NV- Parameters (Inlay NV or NV Items): This data is responsible for unique configurations of the communication module, and changing them can break IMEI or the network.
• 🚫 Radio Band: If you're not an expert in mobile frequencies, don't change those parameters. Incorrect settings will cause you to lose your signal.
• 🚫 Factory Reset in the engineering menu: it's not a regular reset! There can be a complete erasure of the firmware partition.
• 🚫 Battery voltage settings: Changing charge/discharge thresholds can cause the battery to fail.

⚠️ Warning: On the Redmi Note 8T with MIUI 12+ firmware, some dangerous sections of the engineering menu are locked with a password. This is to protect users from accidental changes. If you see a password request when you try to change a setting, it's a sign that you shouldn't touch it.

💡 Tip: Before any changes to the engineering menu, back up your data via Settings → System → Backup. In extreme cases, this will help restore information after a failure.

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The engineering menu is a diagnostic tool, not a tuning tool, and most of the parameters here are for service centers, not for everyday use.

How do you get off the engineering menu and get it back?

If you accidentally change your settings and your smartphone doesn't work properly, don't panic. Most of the time, it's easy to fix the problem:

1. Mild resetting of settings

Many of the options in the engineering menu can be returned to factory values directly from the menu:

• Find the Restore Default or Reset button in the section where you made the changes.
• If there is no such button, try to restart the smartphone - some settings are reset automatically.

2. Hard reset (if the smartphone does not work)

If Redmi Note 8T has stopped turning on or lost network after the changes, reset via Restore mode:

1. Turn off your smartphone.
2. Press the Power Button and Volume up simultaneously until the Mi logo appears.
3. In the recovery menu, select Wipe Data (use volume buttons for navigation, power button for confirmation).
4. Confirm the reset, wait for completion and restart the device.

⚠️ Warning: Hard reset will remove all data from internal memory! If you have important files, try connecting your smartphone to your computer first and copy the data via ADB pull (if the device is still being identified).

3. Flashing through Fastboot

If the smartphone doesn't turn on even after the reset, you just have to play it over the Fastboot.

1. Download the official firmware for the Redmi Note 8T (model M1908C3XG) from the Xiaomi website.
2. Unpack the archive and connect the smartphone to the computer in Fastboot mode (clip Power + Volume down).
3. In the firmware folder, run the file flash_all.bat (Windows) or flash_all.sh (macOS/Linux).

🔧 Note: Flashing will delete all data and return the smartphone to factory status. Use this method only as a last resort.

Frequent Mistakes and How to Avoid Them

Even experienced users sometimes make mistakes when working with the engineering menu, here are the most common problems on the Redmi Note 8T and how to solve them:

💡 Useful tip: If you often work with the engineering menu, install the QuickShortcutMaker app from Google Play. It will help create a shortcut for quick access to Engineer Mode without entering codes.

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Before experimenting with the engineering menu, check if you lose your warranty.Some Xiaomi service centers may refuse repairs if they find signs of changes in system settings.

FAQ: Answers to Frequent Questions