How to fix boot loop in Xiaomi Redmi Note 3

Water-damaged Xiaomi Redmi Note 3 phones require careful handling due to potential electrical hazards.

Rapidly dry the phone with a soft cloth and desiccant packs to prevent short circuits.
Inspect the logic board for damaged components; if found, proceed with component-level repair or replacement as needed.
For minor damage, try cleaning and reflowing the motherboard using a thermal rework station.
As a last resort, consider replacing the entire logic board due to extensive water damage.

Step 1 | Motherboard

Insert a SIM card ejector tool or an unfolded paperclip into the small hole on the left side of the phone's top edge.

Press gently to eject the SIM tray.
Remove the SIM card tray from the device.
To reinsert, orient with gold contacts up and notch to bottom right. Gently press the card into its slot.

Step 2

Insert a putty knife or opening tool into the seam between the phone's back and front covers.

Run the opening tool along the seam to loosen the back cover.
Pry and wiggle the back cover until it comes loose.
The flex cable is located near the top, connected to both halves of the phone.

Avoid tearing the flex cable by pulling the back cover off gently.

Step 3

Disconnect the flex cable using the flat end of a spudger or a pair of tweezers.

Take care not to damage the flex cable during removal.

Remove the phone's back cover.
To reconnect, angle the back cover until the flex cable aligns with its socket.
Use the flat end of a spudger to snap the cable in place by pressing straight down.

Step 4

Remove five plastic cover screws with a Phillips screwdriver.

Step 5

Locate the plastic assembly cover at the bottom of the device.

Insert the flat end of a spudger under the cover.
Pry upwards with the spudger to lift the cover.
Remove the assembly cover once lifted.

Step 6

Disconnect the battery flex cable using the flat end of a spudger.
Use the same method to disconnect the ribbon cable on the left-hand side.

Step 7

Insert the flat end of a spudger under the right-hand corner of the device's bottom.
Pry upwards with the spudger to release the right-hand corner.
Repeat steps 1-2 for the left-hand corner.
Remove the assembly by hand.

Step 8

Peel back the barcode sticker to disconnect it from the battery.

Use your fingers to grasp the black battery adhesive tab and pull outwards firmly until the entire adhesive strip is released.
Repeat this process for the second battery adhesive strip.

Step 9

Position the spudger's flat end under the battery.

Gently lift out the battery using your fingers.

Step 10

Disconnect the ribbon cables by gently prying them away from their connectors with a spudger.

Step 11

Remove the motherboard mounting screws using a Phillips #00 screwdriver.

There are eight screws in total.

Be careful not to strip the screw heads.

Step 12

Remove the small metal piece at the top of the motherboard using a pair of tweezers.

Step 13

Insert an opening tool under the plastic assembly, and use it or your fingers to pry off the cover.

Be careful not to damage any nearby components.

Step 14

Insert the flat end of a spudger under the motherboard.

Pry upwards gently to loosen the motherboard.

OR (if you insist on using two separate steps)

Be cautious when prying the motherboard as it may be fragile.

Insert the flat end of a spudger under the motherboard.
Pry upwards to loosen the motherboard from the phone's front cover.

Step 15

Remove the motherboard from its slot, taking care not to damage any components.

Hold the motherboard by the edges and gently lift it out.
Use the flat end of a spudger to disconnect the cable from the bottom.

Step 16

Remove the motherboard with your fingers.

Step 17 | How to fix boot loop in Xiaomi Redmi Note 3

Inspect the phone's motherboard visually for corrosion.

Apply a small amount of flux to corroded areas using a brush.
Wipe away any corrosion with a soft brush.

Step 18

Overheating can damage other components on the motherboard.

Place a heat shield over unaffected areas.
Use a heat gun to heat the affected area and reflow solder.
Reflowing helps joints become liquid, ensuring smooth electrical flow.

Step 19

Apply a small amount of isopropyl alcohol to the affected areas.

This will help remove any remaining flux residue from the heating process.

Step 20

Inspect the entire motherboard and repeat these steps for any other corroded or rusty areas.