If you have ever been interested in deep customization of Androiddevices, you have probably come across the name Dr. Preston of the legendary expert whose video and guides reveal the hidden capabilities of the operating system. But what exactly does he know about Androidthat is not in the standard instructions? This article is not just a retelling of his advice, but an analysis unique techniques that Preston uses to optimize, repair and customize smartphones from working with ADB to overclocking the processor through the engineering menu.

We analyzed his most popular materials, identified key patterns and systematized them in the form of step-by-step guide. There are no general phrases about “speeding up your phone” - only specific commands, menu paths and warnings about possible risks. If you're ready to get the most out of your Androiddevice, read on.

Who is Dr. Preston and why his advice works

Dr. Preston (real name Brandon Preston) is a software engineer with 15 years of experience working with Android-systems. His channel on YouTube and blog are devoted not so much to reviews of gadgets, but to reverse engineering firmware, searching for vulnerabilities and kernel modifications. Unlike most bloggers, he uses terms like selinux, dm-verity and kernel panic —and explains them in an accessible language.

How his approach differs from the standard guides?

  • 🔍 Working with low-level settings: Preston often uses fastboot i ADB to modify sections that manufacturers block.
  • 🛠️ Fixing "uncorrectable": He shows how to restore bricked-devices (with damaged firmware) without official service.
  • 📡 Bypassing restrictions operators: For example, unlocking VoLTE on uncertified devices.
  • 🔒 Security without compromise: His methods of data encryption and protection from surveillance go beyond standard advice.

It is important to understand: many of his techniques require Unlocking the bootloader (bootloader unlock, which automatically voids the warranty. Preston always warns about this, but explains in detail how to minimize the risks.

📊 Which aspect of Android interests you most?
Performance and overclocking
Crash recovery
Hidden features and features
Security and privacy

Hidden ADB commands that Preston uses

One of Dr. Preston's key tools is Android Debug Bridge (ADB). He doesn't just list standard commands like adb devices, but demonstrates how to use them Bypass system restrictions. For example, forced stop of system applications that usually cannot be disabled.

Here are several commands from his arsenal that are rarely found in open sources:

# Disabling unnecessary system services (requires root)

adb shell pm disable-user --user 0 com.android.quicksearchbox



Changing screen resolution (does not work on all devices)


adb shell wm size 1080x2220



Forced activation of developer mode (if it is hidden by the manufacturer)


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

Preston also actively uses ADB for memory dumps (adb shell dumpsys), which allows you to analyze the operation of applications at the process level. For example, using the command dumpsys meminfo it diagnoses memory leaks in Android 12+that are not visible in the standard task manager.

💡

If the command adb shell returns a "permission denied" error, try add su at the beginning (root required). For example: adb shell su -c "command".

Engineering menu: what the manufacturer is hiding there

Doctor Preston often turns to engineering menu (##4636## or #0#), where settings that are not available in the standard interface are hidden. For example, on devices Samsung through this menu you can:

  • 📶 Force switching networks (2G/3G/4G/5G), even if the operator blocks manual selection.
  • 🔋 Calibrate the battery after replacement, resetting the charge controller data.
  • 🎛️ Adjust sensor sensitivity (accelerometer, gyroscope) for games or VR.
  • 🔊 Activate hidden audio codecs, for example, LDAC or aptX HDif they are disabled by default.

On devices Xiaomi Preston recommends using the code ##6484## for testing display for dead pixels, and on OnePlus — #808## to diagnose the camera module. However, it warns:

What will happen if you accidentally change the settings in the engineering menu?

Some parameters (for example, RAT Selection for networks) can lead to loss of connection. In extreme cases - to a “soft brick” (the device boots, but does not connect to the network).

Manufacturer Engineering menu code What can be configured Risks
Samsung #0# Test of the display, sensors, speakers Low (diagnostics only)
Xiaomi ##4636## Information about the battery, network, usage statistics Medium (you can reset the network settings)
OnePlus #808## Test cameras, checking color rendition Low
Google Pixel ##4636## + Testing Setting up the NFC module, Bluetooth debugging High (you can disrupt the operation of wireless modules)
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The engineering menu on different devices may differ. Always take screenshots of your current settings before making changes!

Overclocking and undervolting: how Preston optimizes the processor

One ​​of the most controversial topics in Dr. Preston's materials is CPU overclocking (overclocking) and undervolting (lowering the voltage to reduce heating). He claims that on some chipsets (for example, Snapdragon 8 Gen 1) you can safely increase performance by 10-15% without a critical increase in temperature.

For this he uses:

  1. Cores Kernel Adiutor or FrancoKernel —for fine-tuning frequencies and voltage.
  2. Modified firmware (for example, LineageOS with patches for overclocking).
  3. Scripts init.d —for automatically applying settings at boot.

An example of its typical configuration for Snapdragon 888:

# Increasing the maximum frequency of a large core (Cortex-X1)

echo 2841600 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq


Reducing voltage at 50 mV for medium cores


echo 850000 > /sys/devices/system/cpu/cpu4/cpufreq/uv_mV_table/1708800

However, Preston always emphasizes:

Make a backup of the EFS partition (IMEI, serial numbers)

Check the idle temperature (should be ≤ 35°C)

Install a monitoring application (for example, CPU Monitor)

Start with minimal changes (plus 5-10% to the frequency)-->

💡

If after overclocking the device starts to randomly reboot, it means the voltage is too low. Return to factory settings!

Restoring "bricks": Preston's methods

One of the most valuable parts of Dr. Preston's expertise is device restoration. after unsuccessful firmware (so-called brickHe identifies three types of "bricks":

  • 🧱 Soft brick: the device turns on, but does not boot (stuck on the logo).
  • 🧱🧱 Hard brick: there is no response to the buttons, but the computer detects the device in fastboot.
  • 🧱🧱🧱 Dead brick: complete absence of signs of life (not detected in any mode).

For soft brick he recommends:

  1. Boot into recovery (usually Volume Up + Power).
  2. Clear cache and data (wipe cache/dalvik).
  3. Reflash only boot.img via fastboot:
fastboot flash boot boot.img

fastboot reboot

For hard brick its method includes:

  1. Use EDL mode (Emergency Download Mode) via testpoints on board.
  2. Firmware of the complete firehosepackage using QFil or Mi Flash.

Preston warns:

⚠️ Attention: Firmware through EDL can erase IMEI serial numbers. Always make a backup EFSpartition before experiments!

Security: how Preston protects data

Unlike most security guides, Dr. Preston focuses not on installing antivirus software, but on system protection mechanisms:

  • 🔐 Encryption FDE/FBE: It explains how to enable full disk encryption even on devices where it is disabled by default.
  • 🛡️ Isolation of applications using Work Profile or Shelter (FOSS-alternative Island).
  • 🕵️ Surveillance blocking through modification of hostsfile and disabling telemetry Google Play Services.
  • 🔑 Hardware security keys: Use YubiKey or Titan Security Key for two-factor authentication.

One of his unique tips is disabling ADB via USB in the backgroundto prevent attacks through connecting to a charger in public places:

adb shell settings put global adb_wifi_enabled 0

adb shell settings put global adb_install_enabled 0

He also recommends using GrapheneOS -firmware with enhanced security, based on Android Open Source Project (AOSP), but with all disabled services Google.

⚠️ Attention: Disabling Google Play Services may disrupt the operation of some applications (for example, banking or geolocation). Before doing this, check compatibility!

Hidden Android functions that manufacturers are silent about

Doctor Preston regularly finds undocumented features in stock firmware. For example:

  • 🎮 Performance mode for games: On some devices Samsung you can activate hidden Game Optimizing Service (GOS)that disables background processes during gameplay. To do this, you need to ADB execute:
adb shell pm enable com.samsung.android.game.gametools

Another feature - hidden DAC in smartphones. Many devices (for example LG V60 or Sony Xperia 1 III) have a hardware digital-to-analog converter, which can be enabled through the engineering menu or modified software. Preston shows how to activate it to improve the sound in your headphones.

He also reveals how:

  • 📱 Customize gestures at the system level (even if the manufacturer has blocked them).
  • 🔄 Force 120 Hz on on screens where this option is hidden.
  • 📡 Activate Dual SIM + eSIM on devices where this is not officially supported.

For the last point it uses command:

adb shell settings put global multi_sim_variant dsds
⚠️ Attention: Some hidden functions may violate the Google Mobile Services (GMS) certification. This will lead to problems with Google Pay, Netflix HD and other services!

FAQ: Answers to frequently asked questions about Preston's methods

❓ Can Preston's advice be applied on any Android device?

No. Most of its methods depend on:

  • Manufacturer (for example, the engineering menu Samsung differs from Xiaomi).
  • Version Android (by Android 13+ many ADB-commands require additional permissions).
  • Bootloader status (unlocked bootloader required for deep modifications).

Always check compatibility on forums like XDA Developers before experiments.

❓ How to get everything back if something went wrong?

Preston recommends:

  1. Reset settings via recovery (wipe data/factory reset).
  2. Reflash the stock firmware via fastboot or Odín (for Samsung).
  3. Restore backup EFS and modemif the network is lost.

If the device does not turn on, try EDL mode (requires a special cable or test points).

❓ Are Preston's methods legal?

From a legal point of view:

  • ✅ Unblocking bootloader and installation of custom firmware are allowed in most countries (including the Russian Federation and the EU).
  • ⚠️ Bypassing DRM-protection (for example, for streaming Netflix in 4K) may violate the terms of use of services.
  • ❌ In some countries (for example, the USA), bypass DMCA-protection is not punishable, but may void the guarantee.
❓ Where can I find Preston's current materials?

Official sources:

He also runs a closed Patreon, where he publishes exclusive guides for cartridges.

❓ Is it possible to repeat his methods without risk?

There are no absolutely safe modifications: However, risks can be minimized:

  • 🔄 Always make a backup via TWRP or OrangeFox Recovery.
  • 📖 Study reviews on the forums before flashing custom kernels.
  • 🛠️ Use proven tools (Magisk, Kernel Adiutor).

Preston often says: "If you are not ready for your device to turn into a brick, don't start."