Panasonic KX-TG6421HGT Service Manual

Also see for KX-TGA641FXT: Service manual Service manual Service manual

Contents

51KX-TG6421HGT/KX-TGA641FXT9.3. Troubleshooting by Symptom (Handset)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 Acousticlevel in detail.(*2) Refer to Check Point (Handset) (P.51)9.3.1. Check Point (Handset)Please follow the items below when BBIC or EEPROM is replaced.Note:After the measuring, suck up the solder of TP.*: Connections (P.64) is required beforehand.The connections of adjustment equipments are as shown in Adjustment Standard (Handset) (P.66).Items CheckPointProcedure Check orReplace Parts(A)* 1.8 V Supply Adjustment 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 thevalue).IC1, Q2, C48,D1, C1, C44,R12, R45,C40, C45, F1(B)* 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.IC1, X1, RA61,R64, R66(C)* EEP-ROM 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).IC1, IC3,R40~R42,C172(D) Charge Control Check &Charge Current MonitorCheck- 1. Apply 3.5 V between CHG(+) and CHG(-) with DC power supply and set cur-rent limit to 250 mA.Confirm the indication of “charging” on LCD.2. Confirm that the current limit LED of DC power supply is ON/OFF.Confirm it after waiting over 1 minute at least.3. Decrease current limit of DC power supply to 100 mA.4. Confirm that the current limit LED of DC power supply is stable. (Current limiteris ON.)(If charge control cannot be confirmed by this procedure, please use battery to hand-set power supply and try again.)IC1, Q4 Q9,D7, R6, R7,F1, C1, R2,R30, R31, R8,R45(E)* Charge Detection (OFF)Check- 1. Stop supplying 3.5 V to CHG (+) and CHG (-).2. Confirm the indication of “charging” has been cleared.IC1, Q4 Q9,D7, R6, R7,F1, C1, R2,R30, R31, R8,R45