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41

[Confirming the operation of IC301 : When monitored 
on an oscilloscope]
Confirm one period of TP305.
(See the figure to the right.)
Count the number of Higher pulses of TP304.
If  the number of pulses and the number of con-
nected microphones are different,
perform procedures b).

Replace the main board if there are no errors, but 
communication is still not available.

a) Replace main board (PNLB1845ZB).
b) Replace parts R1428 or R1448.

Check on communication channel between main unit 
and D-MIC. (One D-MIC connected main unit.)

Execute "TEST_MIC_START 1" command in DIAG 
Mode. (Wait until OK appears.) 
(-Refer to “8.11 DIAG Operation”
 -Audio part Connection Diagram : No1)

Input a sound from D-MIC and confirm so that it can 
be heard.
Either one of the following method is used for confir-
mation method:
 -Confirm that it is output by RCA output terminal with 

an oscilloscope.

 -Connect SP/TV monitor to the RCA output and con-

firm it aurally.

 -Connect only the SP terminal of the headset and 

confirm it aurally.

Go to the next step when it cannot be heard.
Perform procedure a) if it can be heard.

  [Observe the following signals with an oscilloscope.]

(4) OK appears on the console.

If any of the steps (1) through (4) ends in error, 
there may be circuit errors around CN1402, 
IC1401 and 1402, IC301 and IC121 and 201 on 
the main board (PNLB1845ZB).
a) Monitor the pin 4 of IC1402 on the main board. 

Check if the signal level "H" (+3.0 V or more) 
and "L" (0.8 V or less) are observed (No inter-
mediate voltage).
If the criteria mentioned in a) is not met, there 
may be errors in IC301. Perform procedures a) 
shown in Measures column.

b) Monitor the pin 1 of IC1401 on the main board. 

Check if the signal level "H" (+3.0 V or more) 
and "L" (0.8 V or less) are observed (No inter-
mediate voltage).
If the criteria mentioned in b) is not met, perform 
procedures b) shown in Measures column.

c) Confirm that there is no solder bridges or foreign 

objects on the line mentioned above.
If there are unsoldered parts or solder bridges, 
perform procedures c) in Measures column.

a) Replace main board (PNLB1845ZB).
b) Replace IC1401/IC1402.
c) Resolder connector pins.

Proceed to next step if there are no errors.

d) Resolder connector pins.

RXDT

TXDT

42

d) Make sure that there are no solder bridge or 

addition of foreign substances on the route 
above.
If you find a malfunction, go to procedure d).
If there is no malfunction, go to procedure a).

"TEST_MIC_STOP" command is executed and it 
ends.

Analog microphone may be damaged. Connect a 
working one and check if sound is available.
If it is, perform procedures shown in Measures col-
umn.

See Analog Microphone Troubleshooting.

Microphone cable may be damaged. Check conduc-
tivity.
If the cable is damaged, perform procedures shown 
in Measures column.

Replace or repair cables.

Cable between main and sub board may be discon-
nected. Check visually.
If the cable is disconnected, perform procedures 
shown in Measures column.

Insert the cable to CN3 on the sub board 
(PNLB1846ZA-A), or CN505 on the main board 
(PNLB1845ZB).

Cable may be disconnected at sub board 
(PNLB1846ZA-A) or/and HS board (PNLB1846ZA-
C). Check visually.
If the cable is disconnected, perform procedures 
shown in Measures column.

Insert the cable to CN11 on the sub board 
(PNLB1846ZA-A), or CN303 on the HS board 
(PNLB1846ZA-C).

Execute "GET_HS_STAT" command in DIAG Mode.
(-Refer to “8.11 DIAG Operation”
 -Audio part Connection Diagram : No2)

- "00" appears when HS_SP/MIC cable is not 

inserted into the jack.

- "10" appears when HS_MIC cable is inserted into 

the jack.

- "01" appears when HS_SP cable is inserted into the 

jack.

- "11" appears when HS_SP/MIC cable is inserted 

into the jack.

If "11"appears all the time, cable may be discon-
nected. Check again. If the cable is disconnected, 
perform procedures shown in Measures column.

Insert the cable to CN11 on the sub board 
(PNLB1846ZA-A), or CN303 on the HS board 
(PNLB1846ZA-C).

If the above does not apply, signal error related to 
HSout_STAT or HS_STAT may have occurred.

[HSout_STAT line]
Check signal changes at specific points on sub board 
(PNLB1846ZA-A) by inserting and removing headset 
SP terminal.

- Pin 4 of CN11: If the voltage is not 3 V or higher 

when HS_SP cable is inserted and if the voltage is 
not 0.5 V or less when the cable is not inserted, 
check solder joints at HS board, CN11 and Q5. If 
any defective solder joints are discovered, perform 
procedures a) shown in Measures column.

a) Resolder connector pins.

If failure continues, perform procedures b) shown in 
Measures column.

b) Replace parts C68 and Q5.

- E of Q5: If the voltage is not 0.8 V or less when 

HS_SP cable is inserted and if the voltage is not 3 
V or more when the cable is not inserted, check sol-
der joints at pin 2 on IC24, Q5, and R71. If any 
defective solder joints are discovered, perform pro-
cedures a) shown in Measures column. If failure 
continues, perform procedures c) shown in Mea-
sures column.

c) Replace parts Q5, R71, and others.

43

- E of Q16: If the voltage is not 3 V or more when 

HS_SP cable is inserted and if the voltage is not 
0.8 V or less when the cable is not inserted, check 
solder joints at Q16 to pin 7 on CN3. If any defec-
tive solder joints are discovered, perform proce-
dures a) shown in Measures column. If failure 
continues, perform procedures d) shown in Mea-
sures column.

d) Replace part Q16, check the pin 124 of IC121 on 

the main board.

[HS_STAT line]
Check signal changes at specific points on sub board 
(PNLB1846ZA-A) by inserting and removing headset 
MIC terminal.

- Pin 5 of CN11: If the voltage is not 3 V or more 

when HS_MIC cable is inserted into the jack and if 
the voltage is not 0.5 V or less when the cable is 
not inserted, check solder joints at HS board,  CN11 
and Q1. If any defective solder joints are discov-
ered, perform procedures a) shown in Measures 
column.

If failure continues, perform procedures e) shown in 
Measures column.

e) Replace parts C22 and Q1.

- E of Q1: If the voltage is not 0.8 V or less when 

HS_MIC cable is inserted and if the voltage is not 3 
V or more when the cable is not inserted, check sol-
der joints at IC15 and 16, Q1, and R27. If any 
defective solder joints are discovered, perform pro-
cedures a) shown in Measures column. If failure 
continues, perform procedures f) shown in Mea-
sures column.

f) Replace parts Q1, R27 and others.

- E of Q15: If the voltage is not 3 V or more when 

HS_MIC cable is inserted and if the voltage is not 
0.8 V or less when the cable is not inserted, check 
solder joints at Q15 to pin 2 on CN3. If any defec-
tive solder joints are discovered, perform proce-
dures a) shown in Measures column. If failure 
continues, perform procedures g) shown in Mea-
sures column.

g) Replace part Q15, check the pin 123 of IC121 on 

the main board.

Sub board (PNLB1846ZA-A) may be damaged. 
Replace the damaged board with a working one and 
check if sound is available.
- If it is, perform procedures shown in Measures col-

umn.

See Sub Board Troubleshooting.

Check power and clock on main board 
(PNLB1845ZB). Refer to (8.10. Power/clock Failure).

Refer to (8.10. Power/clock Failure).

Check on AMIC connection detecting circuit.

Execute "TEST_AMIC_START" command in DIAG 
Mode.
(-Refer to “8.11 DIAG Operation”
 -Audio part Connection Diagram : No2)

- "OK" appears when AMIC is connected.

- "NG AMIC" appears when AMIC is not connected.

Do not perform "TEST_AMIC_START" continuously.
You must use "TEST_AMIC_STOP" to finish.

If any of the above criteria is not met, there may be 
errors on the circuit between pin 6 of CN6, IC8 and 
pin 3 of CN3 on the sub board and pin 3 of CN505 
and pin 184 of IC121 on the main board.

a) Confirm that there are no solder bridges or unsol-
dered parts on the circuit mentioned above.

44

If there are solder bridges and/or unsoldered parts, 
perform procedures a) shown in Measures column.

*: and check voltage change at following points by 
inserting and removing A-MIC.

b) Pin 2 and 5 on IC8: Check that voltage is approxi-

mately 3 V when A-MIC is connected and 4.5 V or 
more when it is not connected. If the voltage does 
not rise/fall, check solder joints at pin 6 on CN6, 
R33, R34, C35, C36 and IC8. If any defective sol-
der joints are discovered, perform procedures a) 
shown in Measures column.

a) Resolder connector pins.

If the resistance of R33 and R34 are not approxi-
mately 100 [ohm], perform procedures b) shown in 
Measures column.

b) Replace R33 or R34.

c) Pin 3 of IC8: Check that voltage is approximately 

3.6 V regardless of whether the A-MIC is con-
nected or not. If not, check solder joints at R44, 
R45, C42, and IC8.If any defective solder joints 
are discovered, perform procedures a) shown in 
Measures column.

c) Replace R44 or R45.

If R44 is not approximately 1.2 k[ohm] and R45 is not 
approximately 3.3 k[ohm], perform procedures c) 
shown in Measures column.

d) Replace R119.

d) Pin 1 on IC8: Check that voltage is 3 V or more 

when A-MIC is connected and 0.5 V or less when 
it is not connected. If the voltage does not rise/fall, 
check solder joints at IC8, R119 and pin3 on CN3. 
If any defective solder joints are discovered, per-
form procedures a) shown in Measures column.

e) Replace IC8.

R119: If resistance is not approximately 1k [ohm], 
perform procedures d) shown in Measures column.

If any of the above criteria is not met, check voltage 
of all the terminals on IC8. If no error is observed, 
perform procedures e) shown in Measures column.
"TEST_AMIC_STOP" the command   is executed 
and it ends.

Proceed to next step if there are no errors.

Execute "TEST_AMIC_START" command in DIAG 
Mode.
(Wait until OK appears)
(-Refer to “8.11 DIAG Operation”
 -Audio part Connection Diagram : No3)
Check if the audio from A-MIC is transmitted to Audio 
pin jack output terminal. Check with oscilloscope, 
connect SP/TV monitor to Audio pin jack output and 
check by listening, or only connect a headset SP and 
check by listening.

If no sound is available, there may be errors on the 
signal path either at pin 4 and 7 of CN6, IC12, IC15 
and 16, IC19, CN3 on the sub board or at pin 8 of 
CN505, pin 130 of IC121 on the main board.
- Confirm that there are no solder bridges or unsol-

dered parts on the circuit mentioned above.
If any defective solder joints are discovered, per-
form procedures a) shown in Measures column.

- Check if AC waveform is observed at pin 1 and 2 of 

IC19.
Check spread of signal from each IC's input/output, 
and perform procedures b) in Measures column if 
there is disconnected area.
Execute "TEST_AMIC_STOP" command and quit 
DIAG Mode.

a) Resolder connector pins.
b) Replace peripheral parts on the defective circuit.

Replace the main board if there are no errors, but 
communication is still not available.

Cable between main and sub board may be discon-
nected. Check visually.
If the cable is disconnected, perform procedures 
shown in Measures column.

Insert the cable to CN3 on the sub board 
(PNLB1846ZA-A), or CN505 on the main board 
(PNLB1845ZB).