Phone · Samsung · Galaxy S21 Ultra
Samsung Galaxy S21 Ultra Logic Board Repair
Logic Board Repair guide for the Samsung Galaxy S21 Ultra
Before you begin
Tools
- Heat gun or iOpener
- Precision screwdriver set
- Plastic spudger
- Opening picks
- Tweezers
- Magnifying glass or headlamp
- Soldering iron
- Anti-static wrist strap
Parts / materials
- Isopropyl alcohol (99%)
- Replacement back cover adhesive
- Flux
- Desoldering braid
Safety
- Disconnect the battery before manipulating internal board components to prevent electrical shorts.
- Wear eye protection when heating glass or using micro-soldering tools.
- Use an anti-static wrist strap to prevent ESD damage to sensitive micro-circuits.
Overview
Step-by-step
- 1
Heat the Back Glass
3 minApply a heat gun around the edges of the rear glass cover for two minutes to soften the factory adhesive.
- 2
Slice Back Cover Adhesive
4 minInsert a thin opening pick under the back cover edge and slice along all four sides to separate the adhesive.
- 3
Remove the Back Glass
2 minGently lift the rear glass cover away from the phone chassis and set it aside.
- 4
Unscrew Upper Bracket Assembly
3 minRemove the 15 Phillips screws holding down the wireless charging coil and top protective bracket.
- 5
Detach Wireless Charging Pad
2 minPeel up the wireless charging coil assembly from the frame and set it aside.
- 6
Disconnect the Battery Cable
1 minUse a plastic spudger to pry the battery connector straight up off the logic board.
- 7
Disconnect Display and Interconnect Cables
2 minUnplug the display cable and lower sub-board interconnect cables from their board sockets.
- 8
Disconnect Front Camera
1 minUnclip the front selfie camera ribbon cable from its motherboard connector.
- 9
Disconnect Rear Camera Connectors
2 minCarefully unclip the main rear camera module connectors from the logic board.
- 10
Remove Motherboard Retaining Screws
1 minUnscrew the single Phillips screw securing the top portion of the logic board to the frame.
- 11
Extract the Logic Board
2 minInsert a spudger beneath the top edge of the board and carefully lift it out of the chassis.
- 12
Inspect and Repair Components
15 minExamine the logic board under magnification and use micro-soldering tools to repair damaged components or micro-filters.
- 13
Reseat the Logic Board
2 minAlign the repaired logic board into the frame and lower it gently back into position.
- 14
Reconnect Camera Modules
3 minFasten the board retaining screw, then reattach all rear camera and front camera press connectors.
- 15
Reconnect Main Ribbon Cables
3 minSnap the display, sub-board interconnect, and battery connectors firmly back into place.
- 16
Reinstall Wireless Charging Assembly
4 minPlace the top bracket pad back over the motherboard and secure all 15 Phillips screws.
- 17
Reseal the Rear Glass
3 minApply new perimeter adhesive strips to the chassis edge and press the back glass firmly down.
After your Samsung Galaxy S21 Ultra logic board repair
Power the Galaxy S21 Ultra back on and test the logic board repair function before you put every screw away. Check touch/display response, charging, cameras, buttons, and wireless as relevant to this repair. If something fails after closing the device, reopen carefully and reseat the connectors for this Samsung Galaxy S21 Ultra job before assuming the part is defective. Keep leftover adhesive and screws labeled in case you need a second pass.
Keep learning
Explore more Samsung Galaxy S21 Ultra repair context in the encyclopedia, or open related DIY guides.
