Yamaha PSR-S750 Service Manual page 65

Test No. LCD display
9 009 : Pitch Check
10 010 : Output R Check
11 011 : Output L Check
12 012 : MultiAMP Low Check
13 013 : MultiAMP High Check
14 014 : SP MUTE Check
15 015 : DAC MUTE Check
16 016 : MUTE Check
Test descriptions, judging conditions, etc.
Checking sound pitch.
Pitch accuracy check:
Connect a frequency counter to the [PHONES] jack. (Either L or R)
When the test is executed, a sound is produced with 441 ±0.2 Hz sine wave from the L and R
channels.
Sound production stops when returning to the selection screen with the [START/STOP] button.
Checking the R channel output.
Set the [MASTER VOLUME] control to the maximum position in advance of testing.
* It is not possible to operate the VOLUME control while testing.
Connect a level meter (with a JIS-C fi lter) to each jack. (PHONES L, R, OUTPUT L/L+R, R)
Check the output level of the R channel. (1049 Hz (C5) sine wave) (PHONES L, R: 33 Ω load,
OUTPUT L/L+R, R: 10 kΩ load (2 monaural jacks used simultaneously))
· PHONES L: -45.0 dBu or less
· OUTPUT L/L+R: -60.0 dBu or less
Checking the L channel output.
Set the [MASTER VOLUME] control to the maximum position in advance of testing.
* It is not possible to operate the VOLUME control while testing.
Connect a level meter (with a JIS-C fi lter) to each jack. (PHONES L, R, OUTPUT L/L+R, R)
Check the output level of the L channel. (1049 Hz (C5) sine wave) (PHONES L, R: 33 Ω load,
OUTPUT L/L+R, R: 10 kΩ load (2 monaural jacks used simultaneously))
· PHONES L: -0.2 ± 2 dBu
· OUTPUT L/L+R: +5.3 ± 2 dBu
Checking the multi-amplifi er on the LOW side.
Check that the sound is produced with 1 kHz sine wave from the right and left woofers.
Sound production stops when returning to the selection screen with the [START/STOP] button.
Checking the multi-amplifi er on the HIGH side.
Check that the sound is produced with 5 kHz sine wave from the right and left tweeters.
Sound production stops when returning to the selection screen with the [START/STOP] button.
Checks SP MUTE.
Sound is produced with about 1049Hz (C5) sine wave at a specifi ed level of the L and R chan-
nel. Switch between MUTE ON (sound muted) and MUTE OFF (sound produced) with the
[TAB 2 3] button.
MUTE ON [TAB 3]: The SP output is muted.
MUTE OFF [TAB 2]: The SP output is produced.
(The plug should be unconnected from the PHONES terminal.)
Checks DAC MUTE.
Sound is produced with about 1049Hz (C5) sine wave at a specifi ed level of the L and R chan-
nel. Switch between MUTE ON (sound muted) and MUTE OFF (sound produced) with the
[TAB 2 3] button.
MUTE ON [TAB 3]: The SP output and PHONES output are muted.
MUTE OFF [TAB 2]: The SP output and PHONES output are produced.
(The plug should be unconnected from the PHONES terminal when checking the SP output.)
Checking MUTE.
Set the [MASTER VOLUME] control to the maximum position in advance of testing.
* It is not possible to operate the VOLUME control while testing.
Sound is produced with about 1049Hz (C5) sine wave at a specifi ed level of the L and R chan-
nel. Switch between MUTE ON (sound muted) and MUTE OFF (sound produced) with the
[TAB 2 3] button.
Verify that MUTE relay is not stuck.
MUTE ON [TAB 3]: The SP output and PHONES output are muted.
MUTE OFF [TAB 2]: The SP output and PHONES output are produced.
(The plug should be unconnected from the PHONES terminal when checking the SP output.)
Check output level when MUTE ON is selected.
Connect a level meter (with a JIS-C fi lter) to each jack. (OUTPUT L/L+R, R)
Check the output level.
(OUTPUT L/L+R, R: 10 kΩ load (2 monaural jacks used simultaneously))
OUTPUT L, R: -35.0 dBu or less
PHONES R: -0.2 ± 2 dBu
OUTPUT R: +5.3 ± 2 dBu
PHONES R: -45.0 dBu or less
OUTPUT R: -60.0 dBu or less
PSR-S750/PSR-S950
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