ERICSSON CA638, CF688 Service of the Telephone CHAP5
LZB 115 2508 R1A Service of the Telephone
Chapter 5 - Service of the Telephone
Introduction
This chapter contains Level 3 repair procedures for the CA638 and CF688 Cellular Phones, as well as final
checkout procedures before returning the unit to service.
NOTE
If it is necessary to send the phone to a higher level of service, the data from the
arrival test must be sent with the phone.
NOTE
The telephone must be reflashed whenever it is serviced. Refer to Chapter 4 for the
reflashing procedure.
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Service of the Telephone LZB 119 2508 R1A
Required Tools and Test Equipment
Required Tools
The following are the tools needed to perform Level 3 service on the CA638 and CF688 Cellular Phones:
• Small spanner socket
• Soldering Iron and flux
• T6 Torx screwdriver (preset to 20 Ncm)
• Torx bits no. 6
• Latex gloves
• Torque driver (20n-Cm)
• Small flat-blade screwdriver
• Small Phillips-head screwdriver
• Tweezers
NOTE
For more information regarding Process Tools, refer to the Level 2 Certification
Requirements GSM/DCS, publication number EN/LZB 126 1309.
NOTES
Screwdriver NTZ 112 287 should be calibrated according to section Calibration of
Level 2 Certification Requirements, publication number EN/LZB 126 1309.
Torque for the screwdrivers should be 20, - 1 Ncm.
Screw tools for the torque-screw should be type NTZ 112 288 (torx size no. 6).
The Spanner socket should be type NTZ 112 292.
Required Test Equipment
The following test equipment is needed to perform Level 3 service on the CA638 and CF688 Mobile
Phones:
• Programming interface (NTZ 112 293 or NTZ 112 311)
• System cable (KRY 101 1135/10)
• Antenna cable (NTZ 112 291)
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LZB 115 2508 R1A Service of the Telephone
Repair Flow
The following is the repair flow for Level 3 service. See Figure 5-1.
• Inspection is performed to identify mechanical faults on the phone. Check for mechanical dam-
ages and dust in the display.
• Go/No Go Test is used to measure radio parameters according to GSM specifications.
• On-the-Air Call is made to a stationary telephone to check acoustic functionality.
• On-the-Air Call/HF is made to a stationary telephone using a handsfree kit to check system con-
nector functionality if there is suspicion that HF doesn’t work.
• Warranty Seal is to be placed over the left torx screw at the bottom.
• Repair is carried out of components stated in the Repair Actions. After repair the phone is tested
from inspection again.
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Service of the Telephone LZB 119 2508 R1A
Repair
To higher level
From Customer
Inspection
OK
Go/No Go
Test
OK
On-The-Air Call
OK
Warranty Seal
To Customer
Fail
Fail
Fail
Fail
OK
5-4
Warranty Seal
of service
Figure 5-1. Repair Flow
LZB 115 2508 R1A Service of the Telephone
Common Telephone Failures
Refer to Table 5-1 for a list of common failures of the CA638 and CF688 Mobile Phones, the probable
cause of the failure, and the component to be changed.
Table 5-1. Common Failures
Failure Probable Cause
Phone not getting signal Damaged antenna
Damaged antenna connector
Top Indicator not lit LEDs
Volume keys Bad/Broken or badly positioned dome
foil
Keypad keys not func-
tioning
Display segments missing Display is broken Exchange the display assembly
Phone won’t turn on Bad system connector contacts
Bad keypad Exchange the keypad
Broken system connector
Keypad key “ON” may be damaged
Change antenna
Change antenna connector
Change LEDs
Exchange the dome foil
Exchange the volume keys
Check and clean all contacts at
system connector and contact
pads on the PCB
Exchange connector
Check and, if necessary,
exchange the keypad
Action
Phone doesn’t power up
when flip opened
No audio Sound channel at flip may be clogged*
Battery not charging Battery or system connector may be
Peripherals not
functioning
* For CF688 only.
All other measurements are not possible to repair at Level 3. Send the phone to a higher level of service.
Active flip* may be broken Exchange the flip *
Clean or exchange flip *
Contacts at system connector may be
broken
Microphone broken
Earphone broken
damaged
System connector may be damaged
Check and exchange system
connector
Exchange microphone
Exchange earphone
Check and Exchange battery
Check and clean all contacts at
system connector and contact
pads on PCB
Check and exchange system
connector
Check and exchange system
connector
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Service of the Telephone LZB 119 2508 R1A
Exchangeable Parts
The following are the exchangeable parts for the CA638 and CF688 Mobile Phones. See Figure 5-2 and
Figure 5-3.
NOTE
Use both figures as references when reading the following list.
1. Frame
2. Antenna
3. Antenna Connector
4. Buzzer
5. Front cover
6. Display assembly(includes LCD, light guide, and LCD connector)
7. Keypad
8. System connector
9. Warranty seal
10. SIM cover
11. SIM reader
12. Microphone
13. Microphone gasket
14. Flip Door *
15. Hinge *
16. Side Volume keys *
See Figure 5-9, Figure 5-17 and Figure 5-18 for the following replaceable components:
• Dome foil (For side keys)
• Light emitting diodes (LCD)
• Light emitting diodes (Keypad)
• Capacitor (Clock backup)
• Loudspeaker connector
* Note: Only on CF688.
Please contact your Regional Service Manager for the latest spare parts list with part numbers and pricing.
NOTE
The spare parts lists distributed by the Regional Service Managers are more detailed
than the information in this manual. Please reference the item name and the phone
model when requesting spare parts information.
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LZB 115 2508 R1A Service of the Telephone
Figure 5-2. CA638 Exchangeable Parts
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