Samsung Galaxy S21 Plus Motherboard Replacement Step-By-Step Guide

Are you frustrated about the poor processing performance of your Samsung Galaxy S21 Plus? Don't Worry! Follow our easy step-by-step guide to Samsung Galaxy S21 Plus Motherboard Replacement!

Samsung Galaxy S21+ 5G Android smartphone features a large 6.7-inch display and Exynos 2100 chipset with 8 GB RAM. A faulty motherboard will slow down your S21 Plus. You must replace it to restore your phone’s processing speed. 

Let's replace the defective motherboard of your Galaxy S21+!

Step 1 Prepare Mobile Repairing Tools 

Step 1 Prepare Mobile Repairing Tools

Collect all these useful mobile repairing tools to replace the motherboard of your Galaxy S21 Plus:

  • A Hot Air Gun or Hair Dryer to heat the phone 
  • A SIM Card Tray Ejector Pin
  • A Suction Cup
  • A plastic opening pick or tool
  • A spudger or prying tool 
  • A set of screwdrivers
  • Tweezers
  • New adhesive glue
  • A Cotton Bud
  • Isopropyl Alcohol 
  • A clean cloth
  • New Samsung Galaxy S21 Plus Motherboard Replacement

Step 2 Turn Off Your Galaxy S21 Plus

Step 2 Turn Off Your Galaxy S21 Plus
Step 2 Turn Off Your Galaxy S21 Plus2

 

Follow these few steps to switch off your Samsung Galaxy S21 Plus:

  • Press the side and volume down button simultaneously 
  • Wait for a few seconds.
  • A menu will pop up on the screen.
  • Select the power off option.
  • Then tap on the power off option again to switch off your S21+.

Step 3 Eject SIM Card Tray 

Step 3 Eject SIM Card Tray
Step 3 Eject SIM Card Tray 2
  • Find a tiny hole at the bottom edge of your S21+ near the SIM Card Tray. 
  • Insert the SIM Tray ejector pin in this hole.
  • Firmly press the pin until the SIM Tray partially pops out.
  • Remove the SIM card tray of your Samsung Galaxy S21+ with your fingers.
  • Keep the SIM Card Tray in a safe place.

Step 4 Heat The Phone Edges

Step 4 Heat The Phone Edges
  • Adjust medium heat settings on your hot gun or hair dryer. 
  • Keep the hot air gun or hair dryer at least 5 to 10 cm away from your phone. 
  • Heat the phone to melt the adhesive around its edges. Heat will melt the adhesive glue present around all the phone edges.
  • Too much heat can damage the internal components of your S21+.
  • Now it is time to slice the adhesive around the phone edges.

Step 5 Attach A Suction Cup 

Step 5 Attach A Suction Cup
  • Take a suction cup of medium size.
  • Attach the suction cup near the bottom edge of your Galaxy S21 plus back cover.
  • Pull up the suction cup handle.
  • A gap will form between the back cover and the phone frame.

Step 6 Insert The Opening Tool

Step 6 Insert The Opening Tool
  • Insert the plastic pick or opening tool inside the gap between the back cover and the phone frame.
  • Remove the suction cup.

Step 7 Cut The Bottom Adhesive 

Step 7 Cut The Bottom Adhesive
Step 7 Cut The Bottom Adhesive 2
  • Move the plastic opening pick or tool from the phone’s lower right to the lower left corner.
  • Repeat this step twice to cut the bottom edge adhesive of your S21+.
  • If it is difficult to cut the adhesive, you can reheat the phone for 2 to 3 minutes. 

Step 8 Slice The Left Adhesive 

Step 8 Slice The Left Adhesive
Step 8 Slice The Left Adhesive 2
  • Keep moving the opening pick from the lower left to the upper left edge of the phone to cut the left adhesive.

Step 9 Cut Through The Upper Adhesive

Step 9 Cut Through The Upper Adhesive
Step 9 Cut Through The Upper Adhesive2
  • Now move the plastic pick from the phone’s upper left to the upper right corner.
  • Repeat this back-and-forth pick motion to cut the upper edge adhesive.

Step 10 Cut The Right Adhesive 

Step 10 Cut The Right Adhesive
Step 10 Cut The Right Adhesive 2
  • Keep sliding the pick from the upper right to the lower right edge of your S21 Plus to cut the right adhesive.

Step 11 Detach The Rear Cover 

Step 11 Detach The Rear Cover
  • After removing adhesive around all edges of your Galaxy S21+, hold the rear cover of your S21 Plus with your fingers.
  • Remove the rear cover. 

Step 12 Unscrew The Wireless Charging Coil And NFC Antenna Assembly 

Step 12 Unscrew The Wireless Charging Coil And NFC Antenna Assembly
  • There are five 3.9 mm-long screws securing the wireless charging coil and NFC Antenna Assembly.
  • Unscrew all the screws of the wireless charging coil and NFC Antenna Assembly with a screwdriver.
  • Keep these five screws in a safe place.

Step 13 Disconnect The Wireless Charging Coil 

Step 13 Disconnect The Wireless Charging Coil
  • Pry up the Wireless Charging Coil press connector with a spudger to disconnect the wireless charging coil from the motherboard.

Step 14 Disconnect The NFC Antenna

Step 14 Disconnect The NFC Antenna
  • Unclip the NFC Antenna press connector with a spudger to disconnect it from the motherboard.

Step 15 Remove The Wireless Charging Coil And NFC Antenna Assembly 

Step 15 Remove The Wireless Charging Coil And NFC Antenna Assembly
Step 15 Remove The Wireless Charging Coil And NFC Antenna Assembly
  • Insert an opening pick under the charging coil to slice its adhesive.
  • Hold the wireless charging coil and NFC antenna assembly with tweezers.
  • Remove the wireless charging coil and NFC antenna assembly from its recess.
  • Keep it aside.

Step 16 Disconnect The Battery 

Step 16 Disconnect The Battery
  • Lift the battery’s press connector with a spudger to disconnect the battery from the motherboard.

Step 17 Disconnect The Display Cable

Step 17 Disconnect The Display Cable
  • Unclip the display cable’s press connector with a prying tool.

Step 18 Disconnect The Flex Cables 

Step 18 Disconnect The Flex Cables
Step 18 Disconnect The Flex Cables2
  • There are two flex cables connected to your S21 Plus motherboard.
  • Use a spudger to unclip the press connectors of these two flex cables.

Step 19 Unscrew The Top Speaker

Step 19 Unscrew The Top Speaker
  • Unfasten the seven 3.9 mm-long screws of the top speaker of your Galaxy S21+ with a screwdriver.
  • Keep these screws separate from other screws.

Step 20 Disconnect The Top Speaker

Step 20 Disconnect The Top Speaker
  • Detach the earpiece speaker’s press connector with a spudger to disconnect it from the motherboard.

Step 21 Remove The Top Speaker 

  • Pry up the top speaker with a prying tool from its recess.
  • Remove the earpiece speaker.

Step 22 Disconnect The Front Camera 

Step 22 Disconnect The Front Camera
  • Unclip the press connector of the front camera with a spudger or prying tool.

Step 23 Disconnect The Power Button 

Step 23 Disconnect The Power Button
  • Disconnect the power button flex cable with a prying tool.

Step 24 Disconnect The Antenna

Step 24 Disconnect The Antenna
  • Unclip the Antenna flex cable with a spudger or opening pick.

Step 25 Remove The Rear Cameras And Motherboard Assembly 

Step 25 Remove The Rear Cameras And Motherboard Assembly
  • Unscrew the rear camera and motherboard assembly.
  • Lift the rear camera and motherboard assembly with a prying tool from its recess.
  • Hold the rear camera and motherboard assembly with your fingers or tweezers.
  • Remove the rear camera and motherboard assembly from the phone.

Step 26 Separate The Rear Cameras From The Motherboard Assembly 

Step 26 Separate The Rear Cameras From The Motherboard Assembly
Step 26 Separate The Rear Cameras From The Motherboard Assembly 2
  • Disconnect the rear camera assembly from the motherboard.
  • Remove the rear camera assembly from the motherboard.

Step 27 Install The New Motherboard 

Step 27 Install The New Motherboard
  • Connect the rear camera assembly to the new S21 Plus Motherboard.
  • Install the new motherboard assembly to its recess.

Step 28 Reassemble Your Galaxy S21 Plus

Step 28 Reassemble Your Galaxy S21 Plus

To reassemble your Samsung Galaxy S21+ follow these steps:

  • Reconnect the display cable and the flex cables.
  • Reconnect the battery, power button, and antenna to the motherboard.
  • Fasten up all the screws.
  • Reattach and connect the wireless charging coil and NFC Antenna Assembly to the motherboard.
  • Dip a cotton bud into Isopropyl Alcohol. 
  • Rub this cotton bud around the edges of the phone frame and rear cover.
  • Isopropyl Alcohol will soften the remaining adhesive in 2 minutes. 
  • Wipe away the old adhesive and isopropyl alcohol with a clean cloth.
  • Apply new adhesive around the edges of the rear cover.
  • Fix the rear cover to the phone frame.
  • Let the new adhesive to dry for 15 to 20 minutes.

Wrapping Up 

Congratulations! You have successfully replaced the malfunctioning motherboard of your Samsung Galaxy S21 Plus with our step-by-step guidelines. Turn on your Galaxy S21+ and test the processing performance of your S21 Plus’s new motherboard. Submit the old S21 Plus + motherboard to E-waste for recycling.

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