Panasonic KX-TG8421FXB, Service Manual

Page: 49 / 105

49
KX-TG8421FXB/KX-TG8421FXN/KX-TGA840FXB/KX-TGA840FXN
( H )* Hookswitch Check with
DC Characteristics
- 1. Connect Telephone Socket to Tel-simulator which is connected with 600
Ω
.
2. Set line voltage to 48 V and line current to 40mA at off-hook condition of nor-
mal telephone.
3. Execute the command “hookoff”
4. Confirm that the line current is 40 mA ± 5 mA.
5. Execute the command “hookon”.
6. Confirm that the line current is less than + 0.8 mA.
L1, L2, Q3, R14,
R15, Q4, R16,
R17, D3,
R18~R24,
C15~C17 , D21,
Q5, R27, IC7
( I ) DTMF Generator Check - 1. Connect Telephone Socket to DTMF tester. (Load=600
Ω
)
2. Link Handset and push dial key.
3. Confirm DTMF character.
4. Confirm that the high Group is -6.0 dBm ~ -10.0 dBm.
5. Confirm that the low Group is -8.5 dBm ~ -12.5 dBm.
IC7, R116,
C141, R29, C22,
C23, Q5, D21
( J )* Transmitted Power Con-
firmation
-
ANTI_TP
Remove the Antenna before starting step from 1 to 7.
1. Configure the DECT tester (CMD60) as follows;
<Setting>
• Test mode: FP
• Traffic Carrier: 5
• Traffic Slot: 4
• Mode: Loopback
• PMID: 00000
• RF LEVEL = -70 dBm.
2. Execute the command ”sendchar TST”.
3. Execute the command “sendchar dmv 2 2”.
4. Check that “Signalling Status” has been set to “Locked”, then press “ACCEPT
RFPI”.
5. Initiate connection from Dect tester (“set up connect”)
6. Execute the command “ANT1”.
7. Confirm that the NTP value at ANT is 19.0 dBm ~ 25.0 dBm.
IC7,
C802~C806,
C808~C814,
C820, C819,
C822, C823,
C825, C827,
C826, C834,
C851, C853,
C859~C861,
DA801, DA802,
IC801,
L801~L803,
C855~C858,
R801~R807,
R106, R109,
Q9, C617
( K )* Modulation Check and
Adjustment
-
ANTI_TP
Follow steps 1 to 6 of (J) .
7.Confirm that the B-Field Modulation is -370 ± 30/ +370± 30 kHz/div & Modu-
lated width 690 kHz using data type Fig31.
8.Adjust the B-Field Modulation if required. (Execute the command “readmod”
and “wrtmod xx”, where xx is the value.)
IC7,
C802~C806,
C808~C814,
C820, C819,
C822, C823,
C825, C827,
C826, C834,
C851, C853,
C859~C861,
DA801, DA802,
IC801,
L801~L803,
C855~C858,
R801~R807,
R106, R109,
Q9, C617
( L )* Frequency Offset Check -
ANTI_TP
Follow steps 1 to 6 of (J) .
7.Confirm that the frequency offset is < ± 50 kHz.
IC7,
C802~C806,
C808~C814,
C820, C819,
C822, C823,
C825, C827,
C826, C834,
C851, C853,
C859~C861,
DA801, DA802,
IC801,
L801~L803,
C855~C858,
R801~R807,
R106, R109,
Q9, C617
Items Check
Point
Procedure Check or
Replace Parts