Aiwa CX-ZL900, Service Manual

– 36 –

< TUNER  SECTION >

1. Clock frequency Check

Settings : • Test point : TP2 (CLK)
Method : Set  to AM 1710kHz and check that the test point is

2160kHz 

±

 45Hz.

2. AM VT Check

Settings : • Test point : TP1 (VT)
Method : Set to AM 1710kHz, 530kHz and check that the test

point is less than 8.5V (1710kHz) and more than
0.6V (530kHz).

3. FM VT Check

Settings : • Test point : TP1 (VT)
Method : Set to FM 87.5MHz, 108.0MHz and check

that the test point is more than 0.5V
(87.5MHz) and less than 8.0V (108.0MHz).

4. AM Tracking Adjustment

Settings : • Test point : TP8(Lch), TP9(Rch)

• Adjustment location :
L951(1/3) ...................................... 1000kHz

Method : Set to AM 1000kHz and adjust L951(1/3) to MAX.

5. FM Tracking Check

Settings : • Test point :  TP8(Lch), TP9(Rch)
Method : Set to FM 98.0MHz and check that the test point is

less than 9dB

µ

V.

6. AM IF Adjustment

Settings : • Test point : TP5(Lch), TP6(Rch)

• Adjustment location :
L802 ................................................ 450kHz

7. DC Balance / Mono Distortion Adjustment

Settings : • Test point :  TP3, TP4 (DC Balance)

                  : TP8(Lch), TP9(Rch) (Distortion)

• Adjustment location : L801
• Input level : 60dB

µ

V

Method : Set to FM 98.0MHz and adjust L801 so

that the voltage between TP3 and TP4
becomes 0V 

±

 0.04V.

Next, check that the distortion is less than
1.3%.

< DECK  SECTION >

8. Tape Speed Adjustment (DECK 2)

Settings : • Test tape : TTA–100

• Test point : TP8(Lch), TP9(Rch)
• Adjustment location : SFR1

Method : Play back the test tape and adjust SFR1 so that the

frequency counter reads 3000Hz 

±

 5Hz and 

±

 45Hz

(REV) with respect to forward speed.

9. Head Azimuth Adjustment (DECK 1, DECK 2)

Settings : • Test tape : TTA–330

• Test point : TP8(Lch), TP9(Rch)
• Adjustment location : Head azimuth

adjustment screw

Method : Play back (FWD) the 8kHz signal of the test tape and

adjust screw so that the output becomes maximum.
Next, perform on REV PLAY mode.

10. PB Frequency Response Check (DECK 1, DECK 2)

Settings : • Test tape : TTA–330

• Test point :TP8(Lch), TP9(Rch)

Method : Play back the 315Hz and 8kHz signals of the test

tape and check that the output ratio of the 8kHz signal
with respect to that of the 315Hz signal is within 5dB.

11. PB Sensitivity Check (DECK 1, DECK 2)

Settings : • Test tape : TTA–200

• Test point : TP8(Lch), TP9(Rch)

Method : Play back the test tape and check that the output level of

the test point is 230mV 

±

 3dB.

12. REC/PB Frequency Response Adjustment (DECK 2)

Settings : • Test tape : TTA–602

• Test point : TP8(Lch), TP9(Rch)
• Input signal : 1kHz / 10kHz (LINE IN)
• Adjustment location : SFR351 (Lch)

SFR352 (Rch)

Method : Apply a 1kHz signal and REC mode. Then adjust

OSC attenuator so that the output level at the TP5,
TP6 becomes -20VU. Record and play back the 1kHz
and 10kHz signals and adjust SFRs so that the output of
the 10kHz signals becomes 0dB 

±

 0.5dB with respect to

that of the 1kHz signal.

13. REC/PB Sensitivity Check (DECK 2)

Settings : • Test tape : TTA–602

• Test point : TP8(Lch), TP9(Rch)
• Input signal : 1kHz (LINE IN)

Method : Apply a 1kHz signal and REC mode. Then adjust

OSC attenuator so that the output level at TP5, TP6
becomes 0VU. Record and play back the 1kHz signals
and check that the output is 0dB 

±

 3.5dB.

< MICON  SECTION >

14.

µ

-CON OSC Adjustment

Settings : • Test point : TP7 (O-KSCAN)

• Adjustment location : L101

Method : Insert AC plug while pressing TUNER function key.

Adjust L101 so that the frequency at the test point is
208.80Hz 

±

 0.21Hz.