Panasonic KX-TG2448BXF User manual

© 2005 Panasonic Communications Co., Ltd. All
rights reserved. Unauthorized copying and
distribution is a violation of law.
KX-TG2448BXF
KX-TG2448BXS
KX-TGA254BXF
KX-TGA254BXS
2.4 GHz Digital Cordless Phone
Blue Version
Silver Version
(for Asia, Middle Near East and Other areas)
Telephone Equipment
ORDER NO. KM40512964CE

1 ABOUT LEAD FREE SOLDER (PbF: Pb free) 4
1.1. Suggested PbF Solder 4
1.2. How to Recognize that Pb Free Solder is Used 5
2 FOR SERVICE TECHNICIANS 5
3 CAUTION 5
4 OPERATING INSTRUCTIONS 6
4.1. Battery 6
4.2. Location of Controls 8
4.3. Display 9
4.4. Settings 10
4.5. Troubleshooting 14
5 DISASSEMBLY INSTRUCTIONS 17
5.1. Base Unit 17
5.2. Handset 18
6 HOW TO REPLACE THE HANDSET LCD 19
7 TROUBLESHOOTING GUIDE 20
7.1. Check Power 21
7.2. Check Battery Charge 22
7.3. Check Link 23
7.4. Check the RF part 24
7.5. Check Handset Transmission 30
7.6. Check Handset Reception 30
7.7. Check Caller ID 30
8 ADJUSTMENT AND TEST MODE 31
8.1. Test Mode Flow Chart for Base Unit 31
8.2. Test Mode Flow Chart for Handset 35
8.3. X501 (Base Unit), X201 (Handset) Check 39
8.4. Adjust Battery Low Detector Voltage (Handset) 39
8.5. Base Unit Reference Drawing 40
8.6. Handset Reference Drawing 41
8.7. Frequency Table 42
8.8. How to Clear User Setting (Handset Only) 43
9 DESCRIPTION 44
9.1. Frequency 44
9.2. FHSS (Frequency Hopping Spread Spectrum) 44
9.3. Signal Flowchart in the Whole System 46
10 EXPLANATION OF LINK DATA COMMUNICATION 47
10.1. Calling 47
10.2. To Terminate Communication 47
10.3. Ringing 47
11 BLOCK DIAGRAM (BASE UNIT_MAIN) 48
12 BLOCK DIAGRAM (BASE UNIT_RF PART) 49
13 CIRCUIT OPERATION (BASE UNIT_MAIN) 50
13.1. DSP (Digital Speech/Signal Processing: IC501) 50
13.2. EEPROM (IC611) 50
13.3. Power Supply Circuit 51
13.4. Reset Circuit 53
13.5. Telephone Line Interface 54
13.6. Parallel Connection Detect Circuit 55
13.7. Calling Line Identification (Caller ID) 56
13.8. 2.4GHz Mod/Demod Circuit (Base Unit RF Part) 57
14 BLOCK DIAGRAM (HANDSET_MAIN) 58
15 BLOCK DIAGRAM (HANDSET_RF PART) 59
16 CIRCUIT OPERATION (HANDSET) 60
16.1. Construction 60
16.2. Power Supply Circuit 61
16.3. Charge Circuit 62
16.4. Ringer and Handset SP-Phone 62
16.5. Sending Signal 63
16.6. Reception Signal 63
16.7. 2.4GHz Mod/Demod Circuit (Handset RF Part) 64
17 SIGNAL ROUTE 65
18 CPU DATA (BASE UNIT) 66
18.1. IC501 66
19 CPU DATA (HANDSET) 67
19.1. IC201 67
20 EXPLANATION OF IC TERMINALS (RF PART) 68
20.1. IC901 68
21 HOW TO REPLACE A FLAT PACKAGE IC 69
21.1. PREPARATION 69
21.2. FLAT PACKAGE IC REMOVAL PROCEDURE 69
21.3. FLAT PACKAGE IC INSTALLATION PROCEDURE 70
21.4. BRIDGE MODIFICATION PROCEDURE 70
22 CABINET AND ELECTRICAL PARTS (BASE UNIT) 71
Note:
Because CONTENTS 4 is the extract from the Operating Instructions of this model, it is subject to change without notice. You can
download and refer to the original Operating Instructions on TSN Server for further information.
CONTENTS
Page Page
2
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

23 CABINET AND ELECTRICAL PARTS (HANDSET) 72
24 ACCESSORIES AND PACKING MATERIALS 73
24.1. KX-TG2448BXF/BXS 73
25 TERMINAL GUIDE OF THE ICs, TRANSISTORS AND DIODES
74
25.1. Base Unit 74
25.2. Handset 74
26 REPLACEMENT PARTS LIST 75
26.1. Base Unit 75
26.2. Handset 77
26.3. Accessories and Packing Materials 79
26.4. Fixtures and Tools 79
27 FOR SCHEMATIC DIAGRAM 81
27.1. Base Unit (SCHEMATIC DIAGRAM (BASE UNIT_MAIN))
81
27.2. Handset (SCHEMATIC DIAGRAM (HANDSET_MAIN)) 81
28 SCHEMATIC DIAGRAM (BASE UNIT_MAIN) 82
29 SCHEMATIC DIAGRAM (BASE UNIT_RF PART) 84
30 SCHEMATIC DIAGRAM (BASE UNIT_OPERATION) 85
31 SCHEMATIC DIAGRAM (HANDSET_MAIN) 86
32 SCHEMATIC DIAGRAM (HANDSET_RF PART) 88
33 CIRCUIT BOARD (BASE UNIT_MAIN) 89
33.1. Component View 89
33.2. Flow Solder Side View 90
34 CIRCUIT BOARD (BASE UNIT_OPERATION) 91
34.1. Component View 91
34.2. Flow Solder Side View 92
35 CIRCUIT BOARD (BASE UNIT_RF PART) 93
36 CIRCUIT BOARD (HANDSET_MAIN) 95
36.1. Component View 95
36.2. Flow Solder Side View 96
37 CIRCUIT BOARD (HANDSET_RF PART) 97
3
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

1 ABOUT LEAD FREE SOLDER (PbF: Pb free)
Note:
In the information below, Pb, the symbol for lead in the periodic table of elements, will refer to standard solder or solder that
contains lead.
We will use PbF solder when discussing the lead free solder used in our manufacturing process which is made from Tin (Sn),
Silver (Ag), and Copper (Cu).
This model, and others like it, manufactured using lead free solder will have PbF stamped on the PCB. For service and repair
work we suggest using the same type of solder although, with some precautions, standard Pb solder can also be used.
Caution
• • •
• PbF solder has a melting point that is 50°F ~ 70° F (30°C ~ 40°C) higher than Pb solder. Please use a soldering iron with
temperature control and adjust it to 700°F ± 20° F (370°C ± 10°C). In case of using high temperature soldering iron, please
be careful not to heat too long.
• • •
• PbF solder will tend to splash if it is heated much higher than its melting point, approximately 1100°F (600°C).
• • •
• If you must use Pb solder on a PCB manufactured using PbF solder, remove as much of the original PbF solder as possible
and be sure that any remaining is melted prior to applying the Pb solder.
• • •
• When applying PbF solder to double layered boards, please check the component side for excess which may flow onto the
opposite side (See the figure below).
1.1. Suggested PbF Solder
There are several types of PbF solder available commercially. While this product is manufactured using Tin, Silver, and Copper
(Sn+Ag+Cu), you can also use Tin and Copper (Sn+Cu), or Tin, Zinc, and Bismuth (Sn+Zn+Bi). Please check the
manufacturer’s specific instructions for the melting points of their products and any precautions for using their product with other
materials.
The following lead free (PbF) solder wire sizes are recommended for service of this product: 0.3mm, 0.6mm and 1.0mm.
4
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

1.2. How to Recognize that Pb Free Solder is Used
(Example: Handset P.C.B.)
IC201
IC249
CN331
IC371
IC374
IC373
50
26
251
12
43
100
76
75 51
R323
R272
C272
R273
C273
1
R227
C227
ANT
TA
TG
C383
C382
C384 FL901
A
C335
C321
R352
R242
R354
R243
R368
R312
RA251
R318
R334
C333
R333
C231
C317
C304 PDN
TDO TMS
TDI TCK
C208
C307
C303
R367
R366
R362
C353
R361
R363
R364
R231
R230
C223
R223
C224
C340
C305
C336
C316
R317
R226
R205 R206 TEST
R251 R252
R256
R258
R257 R261
R207
C209
JTAG
RA201
C205
C204
C246
C219
14
58
MOD_EN
TXO
TXERXE
RSSIRXI
RESET
R225
C225
C212
C215
C201
C202 C214
R204
R203
R331
Q331
D373
D324 D323
LED261
R332
C322
L211
L326
L332
L327
D326
D327
R234
R249 SPM SPP
R201
Q251 Q252
Q373
CA274
CA271
TP_TESTN
R209
C377
C226
R315
R314
C315
C314
R224
C222
R208
R222
C306
C221
R228
IC221
R340 BCK
R232
R376
R377
R351
C243 C244
1
45
8
R241
C241
C354
C313
C311
C312
MICMMICP
C242
R325
C332
C334
L334
L331
R324
C211
C381 C373
L373
D361
D231
D223
D313
D312
L351
L352
X201
Q221
Q231
Q363
Q243
Q253
Q362
Q361
CHG1
BATTP
BATTM
CHG2
RX
TX
VBAT
VSS
IC241
C372
C371
IC381
1
1
3
3
2
2
54
4
132
54
13
54
C361
SHIELD
PQUP11367Z
IC901
KX-TG24**R
KX-TG24**R
PbF
Marked
(Component View)
Note:
The location of the “PbF”mark is subject to change without notice.
2 FOR SERVICE TECHNICIANS
ICs and LSIs are vulnerable to static electricity.
When repairing, the following precautions will help prevent recurring malfunctions.
1. Cover plastic parts boxes with aluminum foil.
2. Ground the soldering irons.
3. Use a conductive mat on worktable.
4. Do not grasp IC or LSI pins with bare fingers.
3 CAUTION
1. Danger of explosion if battery is incorrectly replaced.
2. Replace only with the same or equivalent type recommended by the manufacturer.
3. Dispose of used batteries according to the manufacturer´s Instructions.
5
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4 OPERATING INSTRUCTIONS
4.1. Battery
4.1.1. Battery Installation
4.1.2. Battery Charge
4.1.3. Recharging the Battery
Note for service:
The battery strength may not be indicated correctly if the battery is disconnected and connected again, even after it is fully
charged. In that case, by recharging the battery as mentioned above, you will get a correct indication of the battery strength.
6
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.1.4. Battery Strength
4.1.5. Battery Replacement
4.1.6. Battery Performance
7
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.2. Location of Controls
4.2.1. Base Unit
4.2.2. Handset
8
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.3. Display
4.3.1. Display Items
4.3.2. Troubleshooting (Handset LCD)
9
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.4. Settings
4.4.1. Connections
10
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.4.2. Guide to Handset Programming
11
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.4.3. Dial Lock
4.4.3.1. To turn dial lock on
4.4.3.2. To turn dial lock off
12
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.4.4. Direct Commands
13
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

4.5. Troubleshooting
If the handset display shows error messages, see “Troubleshooting (Handset LCD) (P.9)”for the Cause & Solution.
14
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

15
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

16
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

5 DISASSEMBLY INSTRUCTIONS
5.1. Base Unit
Shown in Fig.- To Remove - Remove -
1Cabinet Cover Screws (2.6 ×14).....(A) ×4
Main P. C. Board Tapes, Solders and Cable
Main P. C. Board
2Cabinet Body Screws (2.6 ×14).....(B) ×6
3Operational P. C. Board Clear Grille
Screws (2.6 ×8).......(C) ×2
Operational P. C. Board
17
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

5.2. Handset
Shown in Fig.- To Remove - Remove -
4Cabinet Cover Screw Cover
Screw (2.6 ×12)........(D) ×1
Screws (2 ×9).............(E ) ×2
Screws (2 ×14)...........(F ) ×2
5Follow the procedure.
6Main P. C. Board Tape and Solders
Screws (2 ×9).............(G ) ×5
Main P. C. Board
18
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

6 HOW TO REPLACE THE HANDSET LCD
19
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS

Cross Reference:
Check Power (P.21)
Check Battery Charge (P.22)
Check Link (P.23)
Check the RF part (P.24)
Check Handset Transmission (P.30)
Check Handset Reception (P.30)
Check Caller ID (P.30)
7 TROUBLESHOOTING GUIDE
20
KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS