Sony-Ericsson K550 Service Manual Trouble Shooting

Trouble Shooting Guide, Mechanical

Applicable for K550i, K550c & K550im

Contents

1 General ................................................................................................................................. 3

2 Power Problems.................................................................................................................... 4

3 Network/Signal Problems......................................................................................................5

4 Audio Problems.....................................................................................................................6

Microphone: ................................................................................................................... 6

Receiver:........................................................................................................................ 6

Rear Speaker:................................................................................................................ 8

5 Key Problems...................................................................................................................... 10

Keyboard: ....................................................................................................................10

Navigation Key:............................................................................................................ 10

Numeric Keyboard: ...................................................................................................... 11

Volume key: ................................................................................................................. 11

Music Player Key: ........................................................................................................ 12

Power Key: ..................................................................................................................13

Camera Key:................................................................................................................14

6 Display Problems ................................................................................................................15

7 Illumination Problems..........................................................................................................17

Keyboard Illumination: ................................................................................................. 17

Navigation Key Illumination: ........................................................................................17

Display Illumination:..................................................................................................... 17

8 Alert Problems..................................................................................................................... 18

Vibrator: .......................................................................................................................18

Rear speaker: .............................................................................................................. 19

9 Charging/Capacity Problems ..............................................................................................21

10 Rear Camera Problems ......................................................................................................22

11 IR Problems ........................................................................................................................ 25

12 SIM Problems...................................................................................................................... 25

13 Data Transfer Problems using a Data Cable ......................................................................26

14 Bluetooth Problems.............................................................................................................26

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Trouble Shooting Guide, Mechanical

15 Memory Stick Problems ...................................................................................................... 27

16 Hands-Free Problems ......................................................................................................... 27

17 Revision History .................................................................................................................. 28

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Trouble Shooting Guide, Mechanical

1 General

This document outlines the mechanical repairs that should be made in an attempt to fix the common failures that are seen in the field. To gain a complete understanding of how to test and repair a unit, this document should be used in conjunction with the Test Instructions, Mechanical and the Working Instructions, Mechanical.

NOTE! A unit should always be inspected for liquid damage and flashed with latest software before using the

Mechanical Trouble Shooting Guide. Refer the Mechanical Test Instructions for details regarding inspecting for liquid damage and upgrading software.

NOTE! The camera flash should always be discharged before performing any disassembly. Refer to the “General”

section of the Mechanical Working Instructions for a detailed procedure for discharging the camera flash.

NOTE! If all of the repair actions listed in this document for addressing a problem have been preformed and a unit still

is not working, handle the unit according to your local company directives

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Trouble Shooting Guide, Mechanical

2 Power Problems

Problem Area

Unit will not Power On

Items to Inspect

Check whether the keyboard illuminates 15 to 20 seconds after pressing the power key

Inspect battery connector

Inspect the power key and the power key’s switch

Repair Action

If illumination of the keyboard is detected, refer to the “Display Problems” section

• If dirty or oxidized – Clean

• If damaged – Send to an electrical

repair location

• Make sure the power key is properly positioned in the phone.

• If dirt or debris is detected – Clean both the key and the switch

• If the key is damaged – Replace it

• If the switch is damaged – Escalate to

an electrical repair level

Inspection Reference

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If the issue is still not resolved!

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

3 Network/Signal Problems

Problem Area

No Signal or Poor Signal

Items to Inspect

Inspect SIM holder

If the issue has not been resolved!

Repair Action Inspection Reference

• If dirty or oxidized – Clean

• If damaged – Escalate to an electrical

repair level

• Clean the antenna-to-board connectors on the circuit board and replace the antenna/speaker box assembly

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If the issue is still not resolved!

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

4 Audio Problems

Problem Area

Microphone:

Receiver:

No sound or poor quality sound

Items to Inspect

Before proceeding !

Inspect the microphone’s external port

If the issue is still not resolved!

Before proceeding !

Check if the receiver’s external ports are clogged

Repair Action

• Perform a setting reset

• If clogged – Clean the microphone

port in the board frame or replace the board frame as determined necessary.

• Escalate to an electrical repair level

• Perform a setting reset

• If clogged – Clean the external ports

in the front cover or replace the front cover and/or receiver as determined necessary

Inspection Reference

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Trouble Shooting Guide, Mechanical

Problem Area

Receiver:

No sound or poor quality sound (Cont.)

Items to Inspect

If the issue has not been resolved!

• Clean the receiver’s contact pads on the circuit board and replace receiver

Repair Action

Inspection Reference

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If the issue is still not resolved!

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area

Rear Speaker:

No sound or poor quality sound

Items to Inspect Repair Action Inspection Reference

Before proceeding !

Inspect whether the rear speaker’s external ports are clogged

• Perform a setting reset

• If clogged – Clean out the rear

speaker’s external ports and replace the rear speaker cloth

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Trouble Shooting Guide, Mechanical

If the issue has not been resolved!

• Clean the rear speaker’s contact pads on the circuit board and replace antenna/speaker box assembly

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If the issue is still not resolved!

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

5 Key Problems

Problem Area

Keyboard:

None of the keys on the keyboard are functioning (excluding the navigation key)

Items to Inspect

Inspect whether the keyfoil assembly is properly connected to the circuit board

Inspect each half of the keyfoil to circuit board connection

If the issue has not been resolved !

Repair Action

• If improperly connected Reestablish proper connection

• If dirty or oxidized – Clean both halves of the connection

• If the portion of the connection on the keyfoil assembly is damaged Replace the keyfoil assembly

• If the portion of the connection on the circuit board is damaged – Send to an electrical repair location

• Replace the keyfoil assembly, if it has not already been replaced

Inspection Reference

Navigation Key:

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If the issue is still not resolved!

Perform the following action !

• Escalate to an electrical repair level

Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area

Numeric Keyboard:

A key on the numeric keyboard is not functioning or is intermittent

Items to Inspect

Inspect for debris between and/or damage to the numeric keyboard and the corresponding portion of the keyfoil assembly.

If the issue has not been resolved !

• If debris is found – Clean both parts

• If damage is seen – Replace the

numeric keyboard and/or the keyfoil assembly as necessary

• Replace the numeric keyboard and

Repair Action

Inspection Reference

the keyfoil assembly, if they have not already been replaced

If the issue is still not resolved!

• Escalate to an electrical repair level

Volume key:

A direction of the key is not functioning or is intermittent

Inspect the portion of the volume key that is not functioning and its corresponding switch.

If the issue has not been resolved !

• Make sure the volume key is properly positioned in the front cover.

• If dirt or debris is detected – Clean the volume key and both switches

• If the key is damaged – Replace it

• If the switch is damaged – Escalate

to an electrical repair level

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area

Music Player Key:

Items to Inspect

Inspect the music player key and its switch

• Make sure the music player key is properly positioned in the front cover.

Repair Action

Inspection Reference

• If dirt or debris is detected – Clean both the key and the switch

• If the key is damaged – Replace it

• If the switch is damaged – Escalate

to an electrical repair level

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If the issue has not been resolved !

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area

Items to Inspect

Repair Action

Inspection Reference

Power Key:

Inspect the power key and the power key’s switch

If the issue has not been resolved !

• Make sure the power key is properly positioned in the phone.

• If dirt or debris is detected – Clean both the key and the switch

• If the key is damaged – Replace it

• If the switch is damaged – Escalate

to an electrical repair level

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area

Items to Inspect

Repair Action

Inspection Reference

Camera Key:

Inspect the camera key and its switch

If the issue is still not resolved!

• Make sure the camera key is properly positioned in the front cover.

• Make sure the camera switch is properly positioned in the board frame.

• If dirt or debris is detected – Clean both the camera key and its switch

• If the camera key is damaged – Replace it

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

6 Display Problems

Problem Area

If a display is not functioning

Items to Inspect

Check whether the keyboard illuminates 15 to 20 seconds after pressing the power key

Inspect whether the LCD assembly’s flex film is properly connected to the circuit board

Inspect each half of the LCD to circuit board connection

Repair Action

• If the keyboard does not illuminate, refer to the “Power Problems” section

• If improperly connected - Reestablish proper connection

• If dirty or oxidized – Clean both halves of the connection

• If the portion of the connector on the LCD assembly is damaged - Replace the LCD assembly

• If the portion of the connector on the circuit board is damaged – Escalate to an electrical repair level

Inspection Reference

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If the issue has not been resolved !

If the issue is still not resolved !

• Replace the LCD assembly if it has not been replaced

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area Items to Inspect Repair Action Inspection Reference

If a display has lines or missing pixels

Perform the following action !

• Replace the LCD assembly

If the issue is still not resolved !

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

7 Illumination Problems

Problem Area

Keyboard Illumination:

Neither the numeric or the functional keyboard illuminates

Keyboard Illumination:

A portion of the numeric or functional keyboard does not illuminate

Navigation Key Illumination:

Display Illumination:

Items to Inspect

Perform the following action !

If the issue is still not resolved!

Perform the following action !

If the issue is still not resolved!

Refer to the “Keyboard” sections under “Illumination Problems”

Before proceeding !

Perform the following action !

• Replace the keyfoil assembly

• Escalate to an electrical repair level

• Replace the keyfoil assembly

• Escalate to an electrical repair level

• Perform a setting reset

• Replace the LCD assembly

Repair Action

Inspection Reference

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If the issue is still not resolved !

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

8 Alert Problems

Problem Area

Vibrator:

Items to Inspect

Before proceeding !

Inspect the vibrator contact pads on the circuit board

Perform the following action !

If the issue is still not resolved !

• Perform a setting reset

• If dirty – Clean

• Replace the vibrator

• Escalate to an electrical repair level

Repair Action

Inspection Reference

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Trouble Shooting Guide, Mechanical

Problem Area

Rear speaker:

No sound or poor quality sound

Items to Inspect

Before proceeding !

Inspect whether the rear speaker’s external port is clogged

• Perform a setting reset

• If clogged – Clean out the rear

speaker’s external ports and replace

Repair Action

Inspection Reference

the rear speaker cloth

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Trouble Shooting Guide, Mechanical

Problem Area

Items to Inspect

If the issue has not been resolved!

• Clean the rear speaker’s contact pads on the circuit board and replace antenna/speaker box assembly

Repair Action

Inspection Reference

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If the issue is still not resolved!

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

9 Charging/Capacity Problems

Problem Area

Phone is not charging properly

Items to Inspect

Inspect the battery connector

If the issue has not been resolved !

If the issue is still not resolved !

• If dirty or oxidized – Clean

• If damaged – Send to an electrical

repair location

• Replace the system connector

• Escalate to an electrical repair level

Repair Action

Inspection Reference

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Trouble Shooting Guide, Mechanical

10 Rear Camera Problems

Problem Area

Lines or marks in picture

Items to Inspect

Visually inspect the rear camera’s lens

If the issue has not been resolved !

Repair Action

• If dirty – Clean the rear camera’s lens

• If scratched or damaged – Replace the rear camera module

• Replace the rear camera module, if it has not yet been replaced

Inspection Reference

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If the issue is still not resolved !

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area

Will not capture an image when pressing the camera key

Items to Inspect

To determine whether or not the problem is with the camera button, try capturing an image by pressing the navigation key

• If pressing the navigation key does not take a picture - Send to an

electrical repair location

• If pressing the navigation key does

Repair Action

Inspection Reference

take a picture – Perform the

remaining inspect/repair procedures in this section

Inspect the camera key and its switch

If the issue is still not resolved !

• Make sure the camera key is properly positioned in the front cover.

• Make sure the camera switch is properly positioned in the board frame.

• If dirt or debris is detected – Clean both the camera key and its switch

• If the key is damaged – Replace it

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

Problem Area

Receives a

Items to Inspect

Perform the following action !

• Replace the flash assembly

Repair Action

Inspection Reference

message instructing you to open the lens cover when the lens cover is already open

Camera flash

If the issue has not been resolved !

Perform the following action !

• Escalate to an electrical repair level

• Replace the flash assembly

does not work

If the issue has not been resolved !

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

11 IR Problems

Problem Area

Will not connect with a functional IR device

Items to Inspect

Inspect the IR window

If the issue has not been resolved !

12 SIM Problems

Problem Area

SIM undetected

Items to Inspect

Inspect SIM holder

Repair Action

• If dirty – Clean

• If scratched or damaged – Replace

front cover

• Escalate to an electrical repair level

Repair Action

• If dirty or oxidized – Clean

• If damaged – Send to an electrical

repair location

Inspection Reference

Unit indicates the incorrect SIM is inserted

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If the issue has not been resolved !

Check whether the phone is locked to a particular carrier and whether the correct carrier’s SIM is being used

If the issue has not been resolved !

• Escalate to an electrical repair level

• Use correct carrier SIM or test SIM

• Escalate to an electrical repair level

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Trouble Shooting Guide, Mechanical

13 Data Transfer Problems using a Data Cable

Problem Area

Problem transferring data using a direct connection

Items to Inspect

Perform the following action !

• Clean System Connector.

Repair Action

Inspection Reference

If the issue has not been resolved !

14 Bluetooth Problems

Problem Area

Will not connect with a functional Bluetooth device

Items to Inspect

Inspect the Bluetooth antenna’s contact pads on the circuit board

• Escalate to an electrical repair level

Repair Action

• If dirty – Clean

Inspection Reference

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Trouble Shooting Guide, Mechanical

Inspect the spring fingers of Bluetooth antenna

If the issue has not been resolved !

• If bent or damaged – Replace board frame

• Escalate to an electrical repair level

15 Memory Stick Problems

Problem Area

Phone does not detect memory stick

Items to Inspect

Perform the following action !

16 Hands-Free Problems

Problem Area

Hands-free will not work

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Items to Inspect

Perform the following action !

If the issue has not been resolved!

Repair Action

• Escalate to an electrical repair level

Repair Action

• Replace the system connector

• Escalate to an electrical repair level

Inspection Reference

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Trouble Shooting Guide, Mechanical

17 Revision History

Rev. Date Changes / Comments

A 2007-02-20 First release

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