Tips and tricks to fix REALME C21Y problems. This is cheap version of Realme smartphone that use Unisoc T610 processor together with dedicated GPU (graphic processor unit) Mali-G52 for graphic rendering. This phone does not support 5G connection, but we can use 4G LTE for fast broadband Internet access. The operating system use Android 10 with Realme User Interface.

This phone has elegant design with 6.5 inches LCD size HD resolution with small notch drop at top screen for 5 megapixel front camera. Some users get issues when using REALME C21Y software and hardware. We will try to give more solutions, reviews and information about how to solve REALME C21Y troubles at community.


What are Advantages of REALME C21Y Specifications and Features?

  • Network GSM 3G HSDPA or 4G LTE Dual simcard
  • LCD 6.5 inches 20:9 aspect ratio HD Resolution
  • Processor Octa-core 2×1.8 GHz Cortex-A75 & 6×1.8 GHz Cortex-A55
  • GPU Mali-G52
  • Bluetooth / GPS / Wifi
  • Memory Internal 64 GB with 4 GB RAM
  • Main Camera Dual 13 MP f/2.2 + 2 MP f/2.4
  • Main Camera Features autofocus, LED flash
  • Front Camera 5 MP for video conference and selfie photography
  • Operating System Android 10
  • Battery Li-Po 5000 mAh



How to Fix or Problem Solving for Recovery REALME C21Y hang or not responding or malfunctions or stuck or freezing or bricked ?

This phone work with Octa Core processor max 1.8 Ghz Cortex A75 for run several applications that installed from Google Play Store. This phone has 64 GB internal storage with dedicated external memory slot for MicroSD card.

We need to read many user review before download new or not famous apps, because some of them may contain viruses or keylogger or malware that can make troubles if installed on our REALME C21Y such as hang or become slowly or stuck or broken or frozen or LCD touch screen not responsive. These kind of apps will not get Verified by Play Protect information / icon.

To solve this problems, we need to clean temporary files and caches inside this phone. We also have to remove or uninstall suspected applications that may have viruses or malware. We need to install recommended antivirus on our REALME C21Y like Avast or Norton. This applications will scan all installed apps and give recommendation for our bad or high risk setting. When some troubles still happen, then we have to do hard reset or reformat our phone to factory default.

We have to know that all data will be wiped or removed after finish performing hard reset. All Google account will be removed or deleted from REALME C21Y. Please do not install any APK files from unknown resources for safety reasons.


How to Force Shutdown or Force Soft Reset or Reboot or Restart REALME C21Y ?

With 4 GB RAM for multitasking, this phone still able to run several applications together. However, some installed applications may crash or corrupt. At this time, our REALME C21Y will get hang or stuck or frozen or LCD screen not responsive. We have to force shutdown or force soft reset for remove caches and temporary files.


Please and hold Power Button for several seconds until this phone turn off by itself. Continue to turn it on by press Power Button again. This process will not remove any files and installed application from our REALME C21Y, therefore we can do this process anytime we want.

How to clean temporary files and caches when this phone work properly? By doing soft reset or reboot or restart, the temporary files and caches will be clean up automatically. Please press and hold Power Button until pop-up menu appear on the screen, then choose Power Off / Reboot / Shutdown button.


How to backup data or Contact at REALME C21Y ?

REALME C21Y has MicroSD simcard slot for external memory. We can backup / copy all important files and photos or videos from phone internal memory using default Android file manager, then paste it on MicroSD external memory for backup.

We can connect this phone using USB data cable to computer. After our computer finish recognizing our phone, then we can browse REALME C21Y internal storage using computer file manager.

If our REALME C21Y has already signed in with Google account, by default our contact will be synchronize in the background to Google server. Please make sure we check all contact at Google contact server using Internet browse to make sure backup is done.


Please note: These options bellow may not work for some devices because of firmware update version or hardware troubles or some other possibilities.

#Option 1, Hard Reset REALME C21Y with software menu


  1. Turn on the REALME C21Y
  2. Make sure the battery is not empty
  3. Backup important data at REALME C21Y because all data and applications will be erase or delete
  4. Go to Menu :  Setting 
  5. Choose Tab : General
  6. Press Backup & Reset > Restore factory setting
  7. Better to not check anything at the option if you do not want to erase data at data partition at internal memory
  8. Choose Reset phone 
  9. The REALME C21Y will do the master reset process.


hard reset oppo realme c21y

#Option 2, Hard Reset REALME C21Y Factory Default using Hardware Secret Button Key

If we can not go to menu, or REALME C21Y can not turn on or hang or stuck or frozen so we can not access the menu setting or nothing happen while touch the screen, then try to factory reset with secret button and hardware key

  1. Turn off the REALME C21Y
  2. Make sure the battery REALME C21Y already full or more than 50%
  3. Press together and hold the Power Button + Volume Down Button
  4. If the Logo appear, then release the button, after that we will enter some menu
  5. Choose wipe data / factory reset using Volume Button, and press Power Button to Enter or OK
  6. The REALME C21Y will continue master reset, wait for several minutes until REALME C21Y start like new again.


How to Unlock or Fix or Bypass or Solutions for REALME C21Y forgot password code or security lock screen pattern or pin (lost password)?

With 64 GB internal storage, this phone will keep many important data and private photos videos that taken from rear 13 mp for wide and 2 mp for DoF or 5 mp front camera. We have to secure all confidential data from unauthorized people especially when REALME C21Y stolen or lost or away from us.

The fingerprint is fast to access. We can use face detection with 5 megapixel front camera. Please choose secondary protection for backup like screen lock pattern or pin or password. This is important for unlock REALME C21Y after reboot or restart, at this time fingerprint and facial recognizing will not work. However, the problems will start happen when we can not unlock this phone or forgot security pattern / password / pin or fingerprint can not work. What should we do?

The only solutions to bypass forgotten security protection or screen lock pattern or pin or password is doing hard reset or reformat using hardware button combination key like steps at #Option 2 above.

New Android OS already has FRP (Factory Reset Protection). It is important to secure our phone if stolen or lost. If some unauthorized people force hard reset, then new reformatted Android will ask to verified with previous Google account.

Please note, after performing hard reset, some version of Android still ask for password or pin or security protection. We can bypass this protection using software that installed on personal computer. If we are not sure how to do that, please ask Oppo / Realme service center for bypass protections.


Is That Any Secret Code for Doing Format REALME C21Y ?

There is no secret hidden code for REALME C21Y to make it back to factory default. Do the options above for performing hard reset.


How to Format or Erase Phone Memory at REALME C21Y ?

If we want to format and erase all data from all storage, please do hard reset using menu setting like steps at #option 1 above. This process will remove any data from internal storage together with reinstall the Android operating system to factory default.


How to Make Battery of REALME C21Y Stronger, Life Longer and Not Fast to Drain ?

Having 5000 mAh battery capacity is very important to make this phone work full one day without recharger. However, if we use this phone too much for watching movie or playing games several hours continuously, then the battery drain problems will happen.

We have to do some adjustment to make REALME C21Y battery work more longer. Please make LCD screen brightness as low as possible and disable all not use connections like Wifi or GPs or Bluetooht. REALME C21Y does not have NFC connection.