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LG CU400 Hinge Replacement

LG CU400 Hinge Replacement

Ibrahim Momoh

Ibrahim Momoh and 4 other contributors

Last updated on May 7, 2024

1 - 2 hours
Moderate

Introduction

Go to step 1

This guide will show you how to remove and replace the hinge of the LG CU400. The hinge holds the phone together and is responsible for the spring action of the flip phone. This repair would need to happen if the phone would not close or is in two pieces.

What you need

Tools

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  1. LG CU400 Hinge Replacement, Battery: step 1, image 1 of 2 LG CU400 Hinge Replacement, Battery: step 1, image 2 of 2

    • Push the button labeled 'PUSH' on the rear cover.

    Edit

  2. LG CU400 Hinge Replacement: step 2, image 1 of 3 LG CU400 Hinge Replacement: step 2, image 2 of 3 LG CU400 Hinge Replacement: step 2, image 3 of 3

    • Slide the rear cover towards you.

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  3. LG CU400 Hinge Replacement: step 3, image 1 of 2 LG CU400 Hinge Replacement: step 3, image 2 of 2

    • To remove the battery, grasp the top front edge of the battery and pull the battery away from the phone.

    • When installing the new battery, have the metal contacts of the phone match up with the metal contacts of the battery.

    Edit

  4. LG CU400 Hinge Replacement, Bottom Half Assembly: step 4, image 1 of 2 LG CU400 Hinge Replacement, Bottom Half Assembly: step 4, image 2 of 2

    • Remove the sim card by sliding the card out from under the retainer using either your fingers or a spudger.

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  5. LG CU400 Hinge Replacement: step 5, image 1 of 2 LG CU400 Hinge Replacement: step 5, image 2 of 2

    • Remove the rubber covers in the highlighted locations using a metal spudger.

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  6. LG CU400 Hinge Replacement: step 6, image 1 of 2 LG CU400 Hinge Replacement: step 6, image 2 of 2

    • Remove the six 3mm #000 flat Phillips head screws from the back of the phone using a Phillips #000 Screwdriver.

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  7. LG CU400 Hinge Replacement: step 7, image 1 of 2 LG CU400 Hinge Replacement: step 7, image 2 of 2

    • Remove the headphone jack cover with your finger or metal spudger.

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  8. LG CU400 Hinge Replacement: step 8, image 1 of 3 LG CU400 Hinge Replacement: step 8, image 2 of 3 LG CU400 Hinge Replacement: step 8, image 3 of 3

    • Insert the metal spudger between the keypad assembly and back cover assembly and pry the two assemblies apart.

    • Pry gently as to not break the plastic clips that hold the two assemblies together.

    • Work your way around the perimeter of the phone with the metal spudger to separate the two assemblies.

    Edit

  10. LG CU400 Hinge Replacement: step 9, image 1 of 2 LG CU400 Hinge Replacement: step 9, image 2 of 2

    • Once you have worked your way around the perimeter of the phone, you will have access to the components in the bottom half assembly.

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  11. LG CU400 Hinge Replacement, Motherboard: step 10, image 1 of 3 LG CU400 Hinge Replacement, Motherboard: step 10, image 2 of 3 LG CU400 Hinge Replacement, Motherboard: step 10, image 3 of 3

    • You should notice that the number pad is loose and can simply be taken out of the open phone casing.

    Edit

  12. LG CU400 Hinge Replacement: step 11, image 1 of 2 LG CU400 Hinge Replacement: step 11, image 2 of 2

    • Using the spudger, start to gently pry the motherboard from the back of the phone and work your way around the perimeter of the motherboard.

    • There are copper ribbon cables connected to each side of the motherboard leading to the buttons for volume control and the camera that need slid out of the phone casing as the motherboard is being removed.

    • There are three in total, but do not remove the top one from the phone casing yet.

    Edit

  13. LG CU400 Hinge Replacement: step 12, image 1 of 1
    Tool used on this step:
    Tweezers
    $4.99
    Add To Cart

    • Once the motherboard is not locked in place it will still be attached to the back phone casing by two wires, red and black, twisted together.

    • Use tweezers to grab the black piece that these wires are attached to and simply pull it off the motherboard.

    • You may need to flip the phone over so that the screen is facing down. Feel free to move the keypad assembly to the closed position for this step.

    Edit

  14. LG CU400 Hinge Replacement: step 13, image 1 of 1

    • Remove the display ribbon cable from the back of the motherboard using tweezers.

    • Make sure to lift it so that you are pulling the entire thing off at once and not pulling off the flat piece at an angle.

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  15. LG CU400 Hinge Replacement: step 14, image 1 of 1

    • Use tweezers to remove the top ribbon cable, mentioned in step 11, from the hinge area.

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  16. LG CU400 Hinge Replacement: step 15, image 1 of 3 LG CU400 Hinge Replacement: step 15, image 2 of 3 LG CU400 Hinge Replacement: step 15, image 3 of 3

    • Grasp either side of the motherboard and gently lift it away from the phone casing.

    • The motherboard should be completely free of the phone casing, and you should have what is shown in the pictures.

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  17. LG CU400 Hinge Replacement, Top Half Assembly: step 16, image 1 of 1

    • Remove the four rubber covers from the front screen using a metal spudger.

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  18. LG CU400 Hinge Replacement: step 17, image 1 of 2 LG CU400 Hinge Replacement: step 17, image 2 of 2

    • Remove the four 3mm #000 flat Phillips head screws from the front screen using a Phillips #000 Screwdriver.

    Edit

  19. LG CU400 Hinge Replacement: step 18, image 1 of 3 LG CU400 Hinge Replacement: step 18, image 2 of 3 LG CU400 Hinge Replacement: step 18, image 3 of 3

    • Insert the metal spudger in the seam on the top assembly. This will pry the two pieces apart from each other.

    • Continue to work around the perimeter of the phone with the metal spudger.

    • Once you have worked around the perimeter of the phone you should have two halves to the top assembly, the screen assembly and the cover.

    Edit

  20. LG CU400 Hinge Replacement: step 19, image 1 of 3 LG CU400 Hinge Replacement: step 19, image 2 of 3 LG CU400 Hinge Replacement: step 19, image 3 of 3
    Tool used on this step:
    Tweezers
    $4.99
    Add To Cart

    • Set aside the cover half.

    • Using tweezers, carefully disconnect the display ribbon cable from the screen assembly and phone by lifting up on both connections.

    • The display ribbon cable will still be attached to the phone via the hinge. The disconnection of the display ribbon cable in this step is to remove the screen from the screen assembly.

    Edit

  21. LG CU400 Hinge Replacement: step 20, image 1 of 2 LG CU400 Hinge Replacement: step 20, image 2 of 2

    • Grip the screen and ear speaker connected to the screen via red and black wires, and carefully pull the screen away from the screen assembly.

    Edit

  22. LG CU400 Hinge Replacement, Hinge: step 21, image 1 of 2 LG CU400 Hinge Replacement, Hinge: step 21, image 2 of 2
    Tool used on this step:
    Tweezers
    $4.99
    Add To Cart

    • Using tweezers, pull the gray plastic piece that is going around the flex cable out of the hinge area.

    Edit

  23. LG CU400 Hinge Replacement: step 22, image 1 of 2 LG CU400 Hinge Replacement: step 22, image 2 of 2

    • Using the tweezers, slide the metal piece along the center line of the hinge until it clicks into place.

    • This piece will not be completely removed.

    Edit

  24. LG CU400 Hinge Replacement: step 23, image 1 of 1

    • You can now carefully pull apart the phone casing at the hinge by separating them at the left side of the hinge.

    Edit
Conclusion

To reassemble your device, follow these instructions in reverse order.

Author

with 4 other contributors

Ibrahim Momoh

Member since: 10/03/16

107 Reputation

2 Guides authored

Badges: 4

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Team

IUPUI, Team 1-3, Harley Fall 2016 Member of IUPUI, Team 1-3, Harley Fall 2016

IUPUI-HARLEY-F16S1G3

4 Members

14 Guides authored

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