Adjustment <Tuner/Front - Aiwa AV-D77 Service Manual

ADJUSTMENT <TUNER/FRONT>
< TUNER SECTION > < EZ ONLY >
1. Clock Frequency Check
Settings : • Test point : TP2 (CLK)
Method : Set to MW 1602kHz and check that the test point is
2052kHz ± 45Hz.
2. MW VT Check
Settings : • Test point : TP1 (VT)
Method : Set to MW 1602kHz and check that the test point is
less than 8.0V. Then set to MW 531kHz and check that
the test point is more than 0.6V.
3. MW Tracking Adjustment
Settings : • Test point : TP5 (Lch), TP6 (Rch)
• Adjustment location : L981 (1/3)
Method : Set to MW 999kHz and adjust L981 (1/3) so that the
test point becomes maximum.
4. LW VT Adjustment
Settings : • Test point : TP1 (VT)
• Adjustment location : L942
Method : Set to LW 144kHz and adjust L942 so that the test
point becomes 1.3V ± 0.05V.
Then set to LW 290kHz and check that the test point is
less than 8.0V.
5. LW Tracking Adjustment
Settings : • Test point : TP5 (Lch), TP6 (Rch)
• Adjustment location :
L941 ........................... 144kHz
TC942 ......................... 290kHz
Method : Set up TC942 to center before adjustment. The level at
144kHz is adjusted to MAX by L941. Then the level at
290kHz is adjusted to MAX by TC942.
6. AM IF Adjustment
Settings : • Test point : TP5 (Lch), TP6 (Rch)
• Adjustment location :
L772 ........................... 450kHz
7. 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. Then set to FM 87.5MHz and
check that the test point is more than 0.5V.
8. FM Tracking Check
Settings : • Test point : TP5 (Lch), TP6 (Rch)
Method : Set to FM 98.0MHz and check that the test point is
less than 13dBµV.
9. DC Balance / Mono Distortion Adjustment
Settings : • Test point : TP3, TP4 (DC balance)
: TP5(Lch), TP6(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 is 0V ± 300mV. Next,
check the distortion is less than 1.3 %.
< TUNER SECTION > < U ONLY >
1. Clock 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, AM 530kHz and check
that the test point is less than 8.5V(1710kHz) and
more than 0.6V(530kHz).
3. AM Tracking Adjustment
Settings : • Test point : TP8(Lch), TP9(Rch)
• Adjustment location :
L981(1/3) ...................................... 1000kHz
Method : Set to MW 1000kHz and adjust L981(1/3) so that the
test point is max.
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.
Then set to FM 87.5MHz and check that the test point is
more than 0.5V.
5. FM Tracking Check
Settings : • Test point : TP9(Lch), TP9(Rch)
Method : • Set to FM 98.0MHz and check that the test point is
less than 9.0dB.
6. AM IF Adjustment
Settings : • Test point : TP8(Lch), TP9(Rch)
• Adjustment location :
L772 ................................................ 450kHz
7. DC Balance / Mono Distortion Adjustment
Settings : • Test point : TP3, TP4 (DC Balance)
• 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 >
1. µ-CON OSC Adjustment
Settings : • Test point : TP1 and GND
• Adjustment location : L801
Method : Insert AC plug while pressing POWER and ECO key.
Adjust L801 so that the frequency at the test point is
78.69Hz ± 0.08Hz.
– 52 –
TP8(Lch), TP9(Rch) (Distortion)