Sony Ericsson Z750 User manual

Trouble Shooting Guide, Mechanical
1001-5739 2
©Sony Ericsson Mobile Communications AB
Trouble Shooting Guide, Mechanical
Applicable for Z750
Contents
1General .................................................................................................................................2
View of Z750..................................................................................................................2
Service functions in the software...................................................................................3
Misuse and other no warranty issues............................................................................4
Liquid damage ...............................................................................................................5
2Bluetooth Problems...............................................................................................................6
3Camera Problems - Picture Camera.....................................................................................7
4Camera Problems - Video Call Camera – (Z750i Only)........................................................8
5Charging/Capacity Problems ................................................................................................9
6Data Transfer Problems using a Data Cable ........................................................................9
7Display Problems................................................................................................................10
Neither display is functioning.......................................................................................10
Only the outer display is not functioning......................................................................11
Only the inner display is not functioning......................................................................12
8Earphone (Receiver) Problems...........................................................................................13
9FM Radio Problems ............................................................................................................14
10 Hands-Free Problems.........................................................................................................14
11 Illumination Problems..........................................................................................................15
Keyboard Illumination: .................................................................................................15
Inner Display Illumination:............................................................................................15
12 Key Problems......................................................................................................................17
Keyboard: ....................................................................................................................17
Volume Key/Play key:..................................................................................................18
13 Memory Card Problems......................................................................................................19
14 Microphone Problems .........................................................................................................19
15 Network/Signal Problems....................................................................................................20
16 Power Problems..................................................................................................................21
17 Rear Speaker Problems......................................................................................................23
18 SIM Problems......................................................................................................................24

Trouble Shooting Guide, Mechanical
1001-5739 2
©Sony Ericsson Mobile Communications AB 2(25)
19 Vibrator Problems ...............................................................................................................25
20 Revision History..................................................................................................................25
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 to the Mechanical Test Instructions for details regarding upgrading
software.
NOTE! If all of the repair actions listed in this document for addressing a problem have been performed and a unit still
is not working, handle the unit according to your local Sony Ericsson Representative.
View of Z750

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 3(25)
Service functions in the software
The service menu will be accessed with the following key combination.
⇒*⇐⇐*⇐*
The service menu options are:
Service info
Service Settings
Service tests
Text labels
Under the “Service tests” option, the phone’s software has a built in service functionality that allows you to test some of the phones
functions. It looks like this:
Main display
External display
LED/illumination
Keyboard
Speaker
Earphone
Microphone
Vibrating alert
Camera
Video call camera (only applies to Z750i)
Memory card
FM Radio
Real time clock
Total call time
Security
NOTE: Different names may occur depending on language setting and customization.

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 4(25)
Misuse and other no warranty issues
A phone that is damaged due to misuse is not covered by warranty. This section shows many of the signs of misuse that are seen
in the field. Please refer to local directives on how a phone that appears to be damaged due to misuse should be handled.
Below are some examples of damage due to misuse that are not covered by warranty.
Front window broken due to
misuse. LCD cracked due to drop. Clear scratches Mark after drop
Corrosion components on the PCB. Corrosion components on the PCB. Components damaged by liquid System connector damaged by liquid

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 5(25)
Liquid damage
Before any tests are performed, an inspection of the liquid intrusion indicator should be made. If the liquid intrusion
indicator is red, this is an indication of possible liquid exposure. If the liquid intrusion indicator suggests liquid exposure,
please consult your local SEMC representative for handling instructions.
Location of the liquid intrusion indicator
The following pictures show the difference between an indicator that has been in contact with liquid and one that has not.
Not Exposed to Liquid Exposed to Liquid

Trouble Shooting Guide, Mechanical
1001-5739 2
©Sony Ericsson Mobile Communications AB 6(25)
2 Bluetooth Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Inspect the Bluetooth antenna
contact pads on the circuit board •If dirty or oxidized, clean the contact
pads on the circuit board and replace
the system connector
•If damaged, escalate to an electrical
repair level
If the issue is not resolved Æ•Replace the system connector, if it
has not already been replaced
Will not connect
with a functional
Bluetooth device
If the issue is still not resolvedƕEscalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 7(25)
3 Camera Problems - Picture Camera
Problem Area Items to Inspect Repair Action Inspection Reference
Visually inspect the camera window •If dirty, clean the camera window in
the upper rear cover
•If scratched or damaged, replace
upper rear cover
If the issue is not resolved Æ•Replace the camera module
Lines or marks in
picture
If the issue is still not resolvedƕEscalate to an electrical repair level
Inspect camera module connections •Inspect the ZIF connector and make
sure the flex is connected and
secured
•If the flex is damaged, replace the
camera module
•If the ZIF connector is damaged,
replace the upper PWB
If the issue is not resolved Æ•Replace the camera module, if it has
not already been replaced
Camera not
functioning
properly
If the issue is still not resolvedƕEscalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 8(25)
4 Camera Problems - Video Call Camera – (Z750i Only)
Problem Area Items to Inspect Repair Action Inspection Reference
Visually inspect the video telephony
camera window •If dirty, clean the camera window
portion of the upper inner screw
cover
•If scratched or damaged, replace
upper inner screw cover
If the issue is not resolved Æ•Replace the video telephony camera
and the upper PWB assembly
Camera not
working properly
If the issue is still not resolvedƕEscalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 9(25)
5 Charging/Capacity Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Inspect the battery connector •If dirty or oxidized, clean the battery
connector’s contact pins
•If damaged, escalate to an electrical
repair level
If the issue has not been resolved Æ•Replace the system connector and
clean the contact pads on the circuit
board
Phone is not
charging properly
If the issue is still not resolvedƕEscalate to an electrical repair level
6 Data Transfer Problems using a Data Cable
Problem Area Items to Inspect Repair Action Inspection Reference
Perform the following actionƕReplace the system connector and
clean the contact pads on the circuit
board
Problem
transferring data
using a direct
connection
If the issue is still not resolvedƕEscalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 10(25)
7 Display Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Check whether the phone vibrates
when you press the power key and
whether the navigation keypad
illuminates 20 to 25 seconds after the
phone vibrates
If activation of the vibrator and
illumination of the navigation keypad are
not detected, refer to the “Power
Problems” section
Inspect the hinge flex’s connection to
the lower circuit board •If improperly connected, establish
proper connection
•If dirty or oxidized, clean both halves
of the connection
•If the portion of the connection on
the hinge flex is damaged, replace
the hinge flex
•If the circuit board portion of the
connection is damaged, escalate to
an electrical repair level
Neither display is
functioning
Inspect the hinge flex’s upper
connections where it connects to the
upper PWB assembly
•Make sure the upper and lower hinge
flex connections are properly
connected
•If dirty or oxidized – Clean both
halves of both connections
•If either of the two connector portions
on the hinge flex are damaged –
replace the hinge flex
•If either of the two connector portions
on the PWB assembly are damaged
– replace the PWB assembly

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 11(25)
Problem Area Items to Inspect Repair Action Inspection Reference
Inspect each display’s connection to
the PWB assembly •Make sure each display is properly
connected and secured
If the issue is not resolved Æ•Replace the hinge flex, if it has not
already been replaced
Neither display is
functioning
(Cont’d)
If the issue is still not resolved Æ•Escalate to an electrical repair level
Check that the magnet is in place •If it is not, replace the upper front
cover assembly
Inspect outer display’s connection to
the PWB assembly •Make sure the outer display ZIF
connector is properly connected and
secured
•If the flex is damaged, replace the
outer display
•If the ZIF connector is damaged,
replace the upper PWB assembly
Inspect the hinge flex’s lower
connection to the upper PWB
assembly
•Make sure the lower hinge flex
connection is properly connected to
the upper PWB assembly.
•If either half of the connection is
damaged, replace the hinge flex or
PWB assembly as necessary.
If the issue is not resolved Æ•Replace the outer display, if it has
not already been replaced
Only the outer
display is not
functioning
If the issue is still not resolved Æ•Escalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 12(25)
Problem Area Items to Inspect Repair Action Inspection Reference
Check the display connections •Make sure the inner display ZIF
connector is properly connected and
secured
•If the display flex is damaged,
replace the inner display
•If the ZIF connector is damaged,
replace the upper PWB assembly
If the issue is not resolved Æ•Replace the inner display, if it has not
already been replaced
Only the inner
display is not
functioning
If the issue is still not resolved Æ•Escalate to an electrical repair level
Display is not
Illuminating
properly
Refer to the “Illumination Problems” section of this document

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 13(25)
8 Earphone (Receiver) Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Before proceeding Æ•Perform a setting reset
Inspect the receiver’s external port •If clogged – Replace the upper inner
screw cover and the upper front cover
Inspect the connections between the
receiver and upper PWB assembly. •If any of the contacts are dirty, replace
the receiver and clean the contact
pads on the upper PWB assembly
•If the contacts of the receiver are
damaged, replace the receiver.
•If the contact pads on the upper PWB
assembly are damaged, replace the
PWB assembly.
If the issue is not resolved Æ•Replace the receiver, if it has not
already been replaced
No sound or poor
quality sound
If the issue is still not resolved Æ•Escalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 14(25)
9 FM Radio Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Perform the following actionƕReplace the system connector and
clean the contact pads on the circuit
board
FM Radio not
working
If the issue is still not resolvedƕEscalate to an electrical repair level
10 Hands-Free Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Perform the following actionƕReplace the system connector and
clean the contact pads on the circuit
board
Hands-free not
working
If the issue has not been resolved Æ•Escalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 15(25)
11 Illumination Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Keyboard
Illumination:
Bright light spots
shining through
keyboard
Inspect keypad light shield •Install or replace keypad light shield
as needed
Keyboard
Illumination:
The entire
keyboard will not
illuminate
Perform the following actionƕEscalate to an electrical repair level
Keyboard
Illumination:
A portion of the
keyboard does
not illuminate
Perform the following actionƕEscalate to an electrical repair level
Before proceeding Æ•Perform a setting reset
Perform the following actionƕReplace the inner display
Inner Display
Illumination:
Inner Display’s
illumination is
irregular
If the issue has not been resolved Æ•Escalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 16(25)
Problem Area Items to Inspect Repair Action Inspection Reference
Before proceeding Æ•Perform a setting reset
Perform the following actionƕReplace upper PWB assembly
Perform the following actionƕReplace the inner display
Inner Display
Illumination:
Inner Display’s
illumination is dim
If the issue has not been resolved Æ•Escalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 17(25)
12 Key Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Inspect for debris between and/or
damage to the keyboard, keypad light
shield, and the dome array.
•If debris is present between the
keypad light shield and the dome foil,
clean and/or replace parts as
necessary
•If debris is present between the
keyboard and keypad light shield,
clean and/or replace parts as
necessary
If the issue is not resolved Æ•Replace the dome foil, if it has not
been replaced
NOTE: Thoroughly clean the key
contacts on the circuit board before
installing a new dome foil.
If the issue is still not resolvedƕReplace the keyboard and keypad
light shield if they have not been
replaced
Keyboard:
A key on the
keyboard is not
functioning or is
intermittent
If the issue is still not resolvedƕEscalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 18(25)
Problem Area Items to Inspect Repair Action Inspection Reference
Inspect for debris between and/or
damage to the Side Key Assembly
and the side key dome array
•If debris is found between Side Key
Assembly and the side key dome
array, clean and/or replace parts as
necessary
•If the side key assembly is damaged,
replace the side key assembly
•If the side key dome array is
damaged, replace the SIM FPC
assembly
Inspect the SIM FPC assembly’s
connection to the circuit board •If improperly connected, establish
proper connection
•If dirty or oxidized, clean both halves
of the connection
•If the SIM FPC assembly’s portion of
the connection is damaged, replace it
•If the circuit board portion of the
connection is damaged, escalate to
an electrical repair level
If the issue is not resolved Æ•Replace the SIM FPC assembly, if it
has not already been replaced
Volume Key/Play
key:
If the issue is still not resolved Æ•Escalate to an electrical repair level

Trouble Shooting Guide, Mechanical
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©Sony Ericsson Mobile Communications AB 19(25)
13 Memory Card Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Inspect memory card reader •If dirty or oxidized, clean
•If damaged, escalate to an electrical
repair level
Memory card
undetected
If the issue has not been resolved Æ•Escalate to an electrical repair level
14 Microphone Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Before proceeding Æ•Perform a setting reset
Inspect the microphone’s external
port •If clogged, clean microphone’s
external port or replace keyboard and
the lower front cover as necessary.
Also clean the microphone’s port hole
in the circuit board
Inspect the microphone’s port hole in
the circuit board •Clean the port hole in the circuit board
Microphone
If the issue is still not resolvedƕEscalate to an electrical repair level

Trouble Shooting Guide, Mechanical
1001-5739 2
©Sony Ericsson Mobile Communications AB 20(25)
15 Network/Signal Problems
Problem Area Items to Inspect Repair Action Inspection Reference
Perform the following actionƕReplace antenna assembly and
clean the antenna’s contact points
on the circuit board
No Signal or Poor
Signal
If the issue is still not resolvedƕEscalate to an electrical repair level