Introduction
This repair guide was authored by the iFixit staff and hasn’t been endorsed by Google. Learn more about our repair guides here.
Follow this guide to replace the fingerprint sensor for the Pixel 3a. To do so, you will have to remove the motherboard in order to access the fingerprint sensor.
The Pixel 3a’s unreinforced display panel is fragile. If you are reusing the screen, be sure to pay special attention to the warnings in the opening procedure.
If you replace the fingerprint sensor, recalibrate the reader to maintain its functionality.
The trickiest part of the procedure is re-attaching the proximity sensor connector, which requires some patience and finesse.
Tools
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Insert a SIM eject tool, SIM eject bit, or a paper clip into the SIM tray hole.
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Press to eject the tray.
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Take note of the two seams on the phone:
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Screen seam: This seam separates the screen from the rest of the phone. This is where you should pry.
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Frame seam: This is where the plastic frame meets the back cover. It is held in place by screws. Do not pry at this seam.
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Before you begin prying, note the following areas on the screen:
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Screen flex cable: Do not pry deeper than instructed, or you risk damaging this cable.
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Adhesive perimeter: Prying beyond the narrow perimeter without angling the pick will damage the display panel.
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Place a suction cup near the right edge of the screen.
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Pull on the suction cup with strong steady force.
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Insert the pick into the gap, no more than 1 mm.
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With the pick 1 mm in the gap, pivot the pick upwards to a steep angle.
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At this angle, carefully push the pick into the gap about 1/4" (6 mm). The pick should slide in below the OLED panel.
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Slide the pick along the right edge, slicing through the adhesive.
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Leave a pick in place to prevent the adhesive from resealing.
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Slide the pick around the bottom right corner to slice through the adhesive.
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Continue slicing along the bottom edge of the phone and around the left corner.
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Slice through the left edge of the phone, making sure to properly angle the pick below the OLED panel and insert it in no more than 1/4" (6 mm).
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To angle the pick below the OLED panel, insert the point of the pick no more than 1 mm in, angle the pick upwards, and then slowly push the pick in 1/4".
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With all of the edges cut, carefully hinge open the right edge of the screen.
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Use an opening pick to carefully cut through any remaining adhesive.
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With all of the adhesives cut, flip the attached screen glass side down and rest it on top of the phone. The screen flex cable should be loosely arched.
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Carefully peel the black tape covering the screen connector bracket.
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Remove the two 4.4 mm long T3 screws securing the screen connector bracket.
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Remove the screen connector bracket.
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Remove the screen.
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Carefully compare your replacement screen with your original part. You may need to transfer additional components (such as the speaker mesh) to the new part.
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Follow this guide if you are using custom-cut adhesives.
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If you are using double-sided tape such as Tesa tape, follow this guide.
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Remove the fourteen T3 screws of the following lengths securing the plastic midframe:
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Twelve 4.3 mm silver T3 screws
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Two 4.3 mm black T3 screws
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Insert an opening pick into frame seam at the bottom of the phone. This seam sits between the plastic midframe and the back cover.
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Slide the pick along the seam to release the clips holding the plastic midframe.
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Slide the opening pick along the left and right edges of the phone to release the midframe clips.
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Lift the bottom edge of the plastic midframe up but do not remove the midframe. The midframe is still tethered to the phone by the fragile proximity sensor cable at the top edge.
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Use the point of a spudger to carefully pry up and disconnect the proximity sensor connector from the motherboard.
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Remove the plastic midframe.
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Align the top edge of the plastic midframe with the phone.
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Use the point of a spudger to carefully align and push the proximity sensor connector onto the motherboard socket.
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This takes a bit of patience and finesse. Once you have the connector in place, you can also use a finger to gently press the connector onto the socket.
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Use the point of a spudger to carefully pry the proximity sensor out of its recess on the midframe. The sensor is lightly adhered to the midframe.
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Remove the sensor from the midframe. Attach the sensor connector onto its motherboard socket.
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Thread the sensor cable through the midframe and reposition the sensor in the recess. Press down with your finger to adhere the sensor back onto the midframe.
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Use the point of a spudger to pry up and disconnect the battery connector from its motherboard socket.
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Bend the battery flex cable slightly so that it will not accidentally make contact with the socket.
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Use the point of a spudger to pry up and disconnect the interconnect flex cable from its motherboard socket.
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Use the point of a spudger to pry up and disconnect the left squeeze sensor cable connector from its motherboard socket.
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Use the point of a spudger to pry up and disconnect the right buttons connector from its motherboard socket.
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Pry up the right squeeze sensor cable connector from its motherboard socket.
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Insert the flat end of a spudger underneath the right edge of the motherboard and pry upwards to loosen the board.
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Use the point of a spudger to pry up and disconnect the fingerprint sensor cable from its motherboard socket.
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Use the point of a spudger to pry up and disconnect the white antenna cable from its motherboard socket.
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Carefully de-route the cable out of its retaining clips.
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Use the point of a spudger to pry up and disconnect the black antenna cable from its motherboard socket.
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De-route the cable from the retaining clip.
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Heat an iOpener and apply it to the fingerprint sensor for a minute. This will soften the adhesive holding it in place.
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Use your finger to press against the fingerprint sensor from the back of the phone until it loosens from its cutout.
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To reassemble your device, follow these instructions in reverse order.
Repair didn’t go as planned? Check out our Google Pixel 3a Answers community for troubleshooting help.