Troubleshooting By Symptom (Base Unit And Charger Unit) - Panasonic KX-TG8421FXB Service Manual

KX-TG8421FXB/KX-TG8421FXN/KX-TGA840FXB/KX-TGA840FXN
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.
*: The Setting Method of JIG (Base Unit) (P.61) is required beforehand.
The connections of simulator equipments are as shown in Adjustment Standard (Base Unit) (P.63).
Items
(A) 3.0 V Supply Confirma-
tion
(B) 1.8 V Supply Confirma-
tion
(C) Charge Pump
2.5V Supply Confirma-
tion
(D) Charge Pump
3.0V Supply Confirma-
tion
(E)* BBIC Confirmation
(F)* EEPROM Confirmation
(G)* BBIC Clock Adjustment
Check
Point
VDD3 1. Confirm that the voltage between test point VDD3 and GND is 3.0 V ± 0.2 V.
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).
VDD5 1. Confirm that the voltage between test point VDD5 and GND is 2.5 V -0.1/+0.3
V.
VDD4 1. Confirm that the voltage between test point VDD4 and GND is 3.0 V ± 0.2 V.
- 1. BBIC Confirmation (Execute the command "getchk").
2. Confirm the returned checksum value.
Connection of checksum value and program number is shown below.
- 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).
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.
Procedure
48
Check or
Replace Parts
IC1, C31, C32,
R38, R39, C36,
F1, C37, D1
Q8, C75, C614,
C61, IC7
IC7,C625,C631
IC7,C616,C630
IC7, X1, R77,
RA80
IC7, RA402,
C51, R657,
IC401
X1, IC7, R430,
C305