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41

If your unit has below symptoms, follow the instructions in remedy column. Remedies depend on whether you have DECT tester
(*1) or not. 

(*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.41)

Please follow the items below when BBIC or EEPROM or FLASH is replaced.

After the measuring, suck up the solder of TP.
*: The Setting Method of JIG (Base Unit) (P.56) is required beforehand.
The connections of simulator equipment are as shown in Adjustment Standard (Base Unit) (P.58).

Symptom

Remedy (*2)

You don’t have DECT Tester.

You have DECT Tester. 

(Model Number: CMD60)

You cannot dial.

Check item (A) - (I), (R).

Check item (A) - (I), (J) - (N), (R).

You cannot hear the caller’s voice.

Check item (A) - (G), (O), (R).

Check item (A) - (G), (J) - (N), (O), (R).

You cannot use the handset a little away from base unit even if the
handset is within range of the base unit.

-

Check item (J) - (N).

The acoustic transmit level is high or low.

Check item (O).

Check item (O).

The acoustic reception level is high or low.

Check item (O).

Check item (O).

Base unit and handset do not link to each other.

Check item (A) - (I).

Check item (A) - (N).

The unit cannot charge.

Check item (P).

Check item (P).

TAM does not work. (for KX-TG8561 only)

Check item (Q).

Check item (Q).

Items

Check 

Point

Procedure

Check or 

Replace Parts

(A)

2.85 V Supply 

Confirmation

VDD3

1. Confirm that the voltage between test point VDD3 and GND is 2.85 V ± 0.2 V.

IC302, Q310, 

L301, R310, 

R313, R314, 
R315, R316, 
R317, R318, 
R319, C322, 
C341, C342, 

C344, C346 

(B)

1.8 V Supply 
Confirmation

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).

Q301, IC501, 

R311, C311, 

C516, C519

(C) Charge Pump 3.0V

Supply Confirmation

VDD5

1. Confirm that the voltage between test point VDD5 and GND is 3.0 V -0.1/+0.3

V. 

IC501, C511

(D) Charge Pump 3.0V

Supply Confirmation

VDD4

1. Confirm that the voltage between test point VDD4 and GND is 3.0 V ± 0.2 V. 

IC501, C509, 

R507

(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.

IC501, X501, 

R504, RA501

(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).

IC501, RA601, 

IC611, C611, 

R611

(G)* BBIC Clock Adjustment

CKM

1. Confirm that the voltage between testpoint VDD4 and GND is less than 1.0 V.
2. Input Command “ sendchar sfr”, then you can confirm the current value.
3. Check X’tal Frequency. (10.368 MHz ± 100 Hz).
4. If the frequency is not 10.368 MHz ± 100 Hz, adjust the frequency of CKM

executing 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.

IC501, X501, 

C502, R508

che cksum value

4738

program number

DD21RN

KX-TG8551CA

ex.)

che cksum value

FDBA

program number

DD31RN

KX-TG8561CA

ex.)

42

(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

normal 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.

P101, Q141, 
R141, R142, 
Q142, R144, 
R145, D101, 
R161~R167, 
D141, Q161, 
R151, IC501

(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 -3.0 ± 2 dBm.
5. Confirm that the low Group is -6.0 ± 2 dBm.

IC501, C184, 

Q161, D141

(J)*

Transmitted Power 

Confirmation

-

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.

IC501, 

C802~C806, 
C809, C813, 
C820, C822, 
C823, C825, 
C826, C851, 
C853, C837, 
C863, C864, 

DA801, DA802, 

L802~L803, 

C855~C858, 
R806~R807, 
R891, R892, 
Q302, C312, 
C810~C812, 

C859, R312 

(K)* Modulation Check and 

Adjustment

-

ANTI_TP

Follow steps 1 to 6 of (J).

7.Confirm that the B-Field Modulation is -350 ± 50/+350 ± 50 kHz/div using data
type Fig31.

Refer to (J)

(L)* Frequency Offset Check

-

ANTI_TP

Follow steps 1 to 6 of (J).

7.Confirm that the frequency offset is < ± 20 kHz.

Refer to (J) 

(M)*

Sensitivity Receiver 

Confirmation

-

ANTI_TP

Follow steps 1 to 6 of (J).

7.Set DECT tester power to -88 dBm.
8.Confirm that the BER is < 1000 ppm.

Refer to (J) 

(N)*

Power RAMP 

Confirmation

-

Follow steps 1 to 6 of (J).

7.Confirm that Power RAMP is matching.

Refer to (J) 

(O)

Audio Check

-

1. Link with Handset which is connected to Line Simulator.
2. Set line voltage to 48 V and line current to 50 mA.
3. Input -45 dBm (600 

Ω)/1 kHz to MIC of Handset. Measure the Level at Line I/F

and distortion level.

4. Confirm that the level is -2.0 dBm and that the distortion level is <5% at TEL

Line (600 

Ω Load).

5. Input -20 dBm (600 

Ω)/1kHz to Line I/F. Measure the Level at Receiver of

Handset and distortion level (Receive volume set to second position from
minimum).

6. Confirm that the level is -30.0 ± 4 dBm and that the distortion level is <5 % at

Receiver (34 

Ω Load).

IC501, SA101, 

P101, D101, 

Q141, Q142, 

R141, R142, 
R144, R145, 
D141, Q161, 
R163, R164, 
C171, C173, 

R178, C184 

(P)

Charging Check

-

1. Connect Charge Contact 12 

Ω/2 W resistor between charge+ and charge-.

2. Measure and confirm voltage across the resistor is 3.9 V ± 0.4 V.

R371, R372, 

D362, C351

(Q)

TAM Operation 

Confirmation

-

1. TAM Confirmation (Execute the command "sendchar VPI").
2. Confirm the returned Value (Value is "DD37RN 01").

IC501, IC601, 

R601~R607, 
C601, C603, 

Q601

(R)

2.4V Supply 

Confirmation VDD2 

VDD2

1. Confirm that the voltage between test point VDD2 and GND is 2.5V ± 0.2V.

IC501, Q302, 

C312, R312

Items

Check 

Point

Procedure

Check or 

Replace Parts

43

After the measuring, suck up the solder of TP.
The connection of adjustment equipment is as shown in Adjustment Standard (Charger Unit) (P.60).

Items

Check 

Point

Procedure

Check or 

Replace Parts

(A)

Charging Check

-

1. Connect Charge Contact 12 

Ω/2 W resistor between charge+ and charge-.

2. Measure and confirm voltage across the resistor is 3.9 V ± 0.4 V.

R1, R2, D1, F1

44

If your unit has below symptoms, follow the instructions in remedy column. Remedies depend on whether you have DECT tester
(*1) or not. 

(*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 (Handset) (P.44)

Please follow the items below when BBIC or EEPROM is replaced.

After the measuring, suck up the solder of TP.
*: Connections (P.61) is required beforehand.
The connections of adjustment equipment are as shown in Adjustment Standard (Handset) (P.63).

Symptom

Remedy (*2)

You don’t have DECT Tester.

You have DECT Tester. 

(Model Number: CMD60)

Battery strength is not indicated correctly by Battery icon.

Check item (A) - (D), (E) - (G).

Check item (A) - (D), (E) - (G).

You cannot hear the caller’s voice.

Check item (A) - (C), (H), (N).

Check item (A) - (C), (H - (L)) - (N). 

You cannot use handset little away from base unit even if the
handset is within range of the base unit.

-

Check item (I) - (M).

the Audio level is high or low.

Check item (N).

Check item (N).

The SP-Phone level is high or low.

Check item (O).

Check item (O).

Items

Check 

Point

Procedure

Check or 

Replace Parts

(A)* 1.8 V Supply Adjustment

1.8V

1. Confirm that the voltage between test point 1.8V 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 1.8V executing command “VDD XX“(XX is the

value).

IC1, Q1, C44, 

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, RA6, 

R60, R61

(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, RA5, 

C69

(D) Charge Control Check & 

Charge Current Monitor 

Check

-

1. Apply 5.0 V between CHG(+) and CHG(-) with DC power supply and set

current limit to 150 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.

(If charge control cannot be confirmed by this procedure, please use battery to
handset power supply and try again.)

IC1, Q4 Q9, 
Q2, Q3, R2, 

R3, R7, R8, 

R6, R9, C19, 

F1, R45

(E)* Charge Detection (OFF) 

Check

-

1. Stop supplying 5.0 V to CHG (+) and CHG (-).
2. Confirm the indication of “charging” has been cleared.

IC1, Q4 Q9, 
Q2, Q3, R2, 

R3, R7, R8, 

R6, R9, C19, 

F1, R45

checksum value

program number

ex.)

4EE0

DD12RN