Sanyo DS31520 Service Manual page 9

SOUND ADJUSTMENT
1. Connect a color-bar generator to the antenna terminals
with audio signal of 1KHz at 100% modulation.
2. Set the picture controls to the Sports levels
3. Connect oscilloscope + lead to TP21 (pin 75 of IC101)
and – lead to ground.
4. Turn off the receiver and disconnect the AC power cord
(AC 120V line).
5. While pressing the Menu key, reconnect the AC power
cord. The Service Menu will now appear.
6. Select NO. 45 FL (FM Level) with the
7. Adjust the data with the + or – key for an oscilloscope
reading of 0.693 ± 10% VP-P at TP21.
8. Press the MENU key to turn off the Service Menu display
and disconnect the oscilloscope from the chassis.
Figure 7.
MULTI-SOUND SECTION ADJUSTMENTS
Note: Multi-Sound Section must be adjusted after
IC101 (Signal Processor), IC3401 (MTS Decoder), or
IC802 (EEPROM) is replaced.
INPUT LEVEL ADJUSTMENT
1. Connect a signal to the antenna terminals with audio of
1 KH 100% modulation.
Z
2. Turn off the receiver and disconnect the AC power cord
(AC 120V line).
3. Connect voltmeter (RMS) to TP317 and ground.
4. While pressing the Menu key, reconnect the AC power
cord. The Service Menu will now appear.
5. Select NO. 60 ATT (Attenuation) with the
6. Adjust the + or – key for a voltmeter reading of 400 ± 20
mVrms at TP317.
SEPARATION ADJUSTMENT
7. Turn off the receiver and disconnect the AC power cord
8. Connect oscilloscope CH1 to TP317 and CH2 to TP318
9. Connect an MTS TV/Stereo generator to antenna terminal.
10. While pressing the Menu key, reconnect the AC power
11. Select pilot, 300Hz audio frequency and Left modulating
or key. 12. Select NO. 61 WDB (Wideband) with the
13. Adjust the + or – key for minimum low frequencies at
14. Select 4 KHz audio frequency and Right modulating signal.
15. Select NO. 62 SPC (Spectral) with the
16. Adjust the + or – key for minimum high frequencies at
Repeat adjustments (steps 11–16) until no further decreases
in amplitude can be obtained. Press the MENU key to turn
0.693 ± 10% VP-P
off the Service Menu display.
PURITY AND CONVERGENCE ADJUSTMENTS
Purity and Convergence have been aligned at the factory.
No re-alignment is necessary.
or key.
— 9 —
(AC 120V line).
and ground.
cord. The Service Menu will now appear.
signal.
TP317. (See Figure 8.)
TP318. (See Figure 8.)
Minimize L leakage
TP317 (R)
300Hz
TP318 (L)
Figure 8. Separation Adjustments
or key.
or key.
Minimize R leakage
4KHz