Panasonic KX-TG8421EB, Service Manual

Page: 48 / 110

48
KX-TG8421E/KX-TG8422E/KX-TG8423E/KX-TG8424E/KX-TGA840E
9.2. Troubleshooting by Symptom (Base Unit and Charger Unit)
If your unit has below symptoms, follow the instructions in remedy column. Remedies depend on whether you have DECT tester
(*1) or not.
Note:
(*1) A general repair is possible even if you don’t have the DECT tester because it is for confirming the levels, such as Acoustic
level in detail.
(*2) Refer to
Check Point (Base Unit) (P.48)
9.2.1. Check Point (Base Unit)
Please follow the items below when BBIC or EEPROM or FLASH is replaced.
Note:
After the measuring, suck up the solder of TP.
*:
PC Setting (P.61) is required beforehand.
The connections of simulator equipments are as shown in Adjustment Standard (Base Unit) (P.63).
Items Check
Point
Procedure Check or
Replace Parts
( A ) 3.0 V Supply Confirma-
tion
VDD3 1. Confirm that the voltage between test point VDD3 and GND is 3.0 V ± 0.2 V. IC1, C31, C32,
R38, R39, C36,
F1, C37, D1
( B ) 1.8 V Supply Confirma-
tion
VDD1 1. Confirm that the voltage between test point VDD1 and GND is 1.8 V ± 0.02 V.
2. Execute the command “VDD”, then check the current value.
3. Adjust the 1.8V voltage of VDD1 executing command “VDD XX“(XX is the
value).
Q8, C75, C614,
C61, IC7
( C ) Charge Pump
2.5V Supply Confirma-
tion
VDD5 1. Confirm that the voltage between test point VDD5 and GND is 2.5 V -0.1/+0.3
V.
IC7,C625,C631
( D ) Charge Pump
3.0V Supply Confirma-
tion
VDD4 1. Confirm that the voltage between test point VDD4 and GND is 3.0 V ± 0.2 V. IC7,C616,C630
( E )* BBIC Confirmation - 1. BBIC Confirmation (Execute the command “getchk”).
2. Confirm the returned checksum value.
Connection of checksum value and program number is shown below.
IC7, X1, R77,
RA80
( F )* EEPROM Confirmation - 1. EEP-ROM Confirmation (Execute the command "sendchar EPV").
2. Confirm the returned Value (Value for reference is written at "EEPROM C/
SUM" in Software_Version_Table.xls).
IC7, RA402,
C51, R657,
IC401
( G )* BBIC Clock Adjustment CLK 1. Input Command “ sendchar WWD ff 48 IC 8006”
2. Confirm that the voltage between testpoint VDD4 and GND is less than 1.0 V.
3. Input Command “ sendchar sfr”, then you can confirm the current value.
4. Check X’tal Frequency. (10.368 MHz ± 100 Hz).
5. If the frequency is not 10.368MHz ± 100Hz, adjust the frequency of CLK exe-
cuting the command “sendchar sfr xx xx (where xx is the value)” so that the
reading of the frequency counter is 10.368000 MHz ± 5 Hz.
X1, IC7, R430,
C305