Aiwa XR-MR5 Service Manual page 33

ADJUSTMENT <TUNER / FRONT / CD>
< TUNER SECTION >
1. Clock Frequency Check
Settings : • Test point : TP2 (CLK)
Method : Set to AM 1602kHz and check that the test point is
2052kHz ± 45Hz.
2. AM VT Check
Settings : • Test point : TP1(VT)
Method : Set to AM 1602kHz and check that the test point is
less than 8.0V. Then set to AM 531kHz and check
that the test point is more than 0.6V.
3. AM Tracking Adjustment
Settings : • Test point : TP6(Lch), TP7(Rch)
• Adjustment location :
L981(1/3) ........................................ 999kHz
Method : Adjust L981 (1/3) so that the output becomes
maximum.
4. FM VT Check
Settings : • Test point : TP1 (VT)
Method : Set to FM 108.0MHz and check that the test point is
less than 8.0V.
Set to FM 87.5MHz and check that the test point is
more than 0.5V.
5. FM Tracking Check
Settings : • Test point : TP6(Lch), TP7(Rch)
Method : Set to FM 98.0MHz and check that the test point is
less than 9.0dBµV.
6. AM IF Adjustment
Settings : • Test point : TP6(Lch), TP7(Rch)
• Adjustment location :
L772 ................................................ 450kHz
Method : Adjust L772 so that the output becomes maximum.
7. DC Balance / Mono Distortion Adjustment
Settings : • Test point : TP3, TP4 (DC Balance)
TP6(Lch), TP7(Rch) (Distortion)
• Adjustment location : L771
• Input level : 60dBµV
Method : Set to FM 98.0MHz and adjust L771 so that the
voltage between TP3 and TP4 becomes 0V ± 0.04V.
Next, check that the distortion is less than 1.3%.
< FRONT SECTION >
8. µ-CON Clock Adjustment
Settings : • Test point : TP1 (K-SCAN), TP2 (GND)
• Adjustment location : L201
Method : Insert AC plug while pressing of "TUNER" key and
"ERASE" function key.
Connect a frequency counter across TP1 and TP2.
Then adjust L201 so that the test point becomes
209.789Hz ± 0.21Hz.
< CD SECTION >
9. Focus Bias Adjustment
Settings : • Test disc : TCD–782
• Test point : TP1 (FE), TP5 (VREF)
• Adjustment location : SFR130
Method : Play back the test disc (TCD–782, Track No. 2) and
adjust SFR130 so that the voltage between the test point
becomes 0mV ± 10mV.
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