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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