Aiwa NSX-SZ50 Service Manual page 28

< TUNER SECTION >
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, 531kHz and check that the test
point is less than 8.0V (1602kHz) and more than
0.6V (531kHz).
3. 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 1.5V ± 0.05V. Then set to LW 290kHz and
check that the test point is less than 8.0V.
4. 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).
5. MW Tracking Adjustment
Settings : • Test point : TP8(Lch), TP9(Rch)
• Adjustment location :
L951(1/3) ........................................ 999kHz
Method : Set to MW 999kHz and adjust L951(1/3) so that the
level at the test point becomes maximum.
6. LW Tracking Adjustment
Settings : • Test point : TP8 (Lch), TP9 (Rch)
• Adjustment location :
L941 ..........................................................144kHz
TC942 ........................................................290kHz
Method : Set up TC942 to center before adjustment.
Adjust L941 so that the level at 144kHz becomes
maximum. Then adjust TC942 so that the level at
290kHz becomes maximum.
7. 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 13dBµV.
8. AM IF Adjustment
Settings : • Test point : TP8(Lch), TP9(Rch)
• Adjustment location :
L802 ................................................ 999kHz
9. DC Balance / Mono Distortion Adjustment
Settings : • Test point : TP3, TP4 (DC Balance)
TP8(Lch), TP9(Rch) (Distortion)
• Adjustment location : L801
• Input level : 60dBµV
Method : Set to FM 98.0MHz and adjust L801 so that the voltage
between TP3 and TP4 becomes 0V ± 0.3V.
Next, check that the distortion is less than 1.3%.
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< DECK SECTION >
10. 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.
11. 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.
12. PB Frequency Response Check (DECK 1, DECK 2)
Settings : • Test tape : TTA–300
• 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.
13. 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 130mV ± 3dB.
14. REC/PB Frequency Response Adjustment (DECK 2)
Settings : • Test tape : TTA–602
• Test point : TP8(Lch), TP9(Rch)
• Input signal : 1kHz / 8kHz (LINE IN)
• Adjustment location : SFR451 (Lch)
Method : Apply a 1kHz signal and REC mode. Then adjust
OSC attenuator so that the output level at the TP8,
TP9 becomes -20VU. Record and play back the 1kHz
and 8kHz signals and adjust SFRs so that the output of
the 8kHz signals becomes 0dB ± 0.5dB with respect to
that of the 1kHz signal.
15. 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 TP8, TP9
becomes 0VU. Record and play back the 1kHz signals
and check that the output is –2dB ± 3.0dB.
< FRONT SECTION >
16. µ-CON OSC Adjustment
Settings : • Test point : TP7 and GND
• Adjustment location : L331
Method : Insert AC plug while pressing POWER and TUNER
function keys. Adjust L331 so that the frequency at the
test point is 153.84Hz ± 0.15Hz.
SFR452 (Rch)