Yamaha PSR-E473 Service Manual page 22

PSR-E473
No. Inspection items
019 MUTE Check
021 HP Insertion and
Extraction Check
022 AUX Check
22
Procedures for selection and execution of test items
Checks whether the Mute function works properly.
1) Press the [START/STOP] button. "MUTE Off" is shown on the LCD and the C5
sound is produced.
2) Press the [+] button, and the muting circuit is activated.
The LCD screen switches to "MUTE On".
3) Confirm that the speakers and the output of the [PHONES] jack and the
[OUTPUT] jack are muted.
4) Press the [-] button, and the muting circuit is deactivated.
The LCD screen switches to "MUTE Off".
5) Confirm that the muting is deactivated for the speakers and the output of the
[PHONES] jack and the [OUTPUT] jack.
6) Press the [START/STOP] button to stop the C5 sound and return to the test item
selection screen.
* When checking the output of the speakers, do not connect anything to the [PHONES]
jack.
Checks whether headphones insertion and extraction work properly.
1) Press the [START/STOP] button."HP In" is shown on the LCD.
2) Connect headphones to the [PHONES] jack. "HP Out" is shown on the LCD.
3) Remove the headphones from the [PHONES] jack. If there are no problems, "HP
OK" is shown on the LCD.
4) Press the [START/STOP] button to return to the test item selection screen.
* If insertion/extraction of headphones is not detected within 60 seconds after the start
of the test, it times out and "HP NG" is shown on the LCD.
Checks whether signal input to the [AUX IN] jack functions properly.
1) Press the [START/STOP] button, and check whether "AUX In" is shown on the
LCD when nothing is connected to the [AUX-IN] jack.
2) Connect an oscillator to the [AUX IN] jack on the rear panel.
When the stereo mini-plug of the connection cable is plugged in to the [AUX IN]
jack, confirm that the LCD display changes to "AUX Out".
3) Connect the level meter to the [PHONES] jack on the rear panel. (Both L and R
channels, 33 Ω load)
4) Input a sine wave (-6.0 dBu, 1 kHz) to the R channel of the [AUX IN] jack.
5) Check the output levels of L and R ch indicated on the Level meter.
No problem if the following conditions are satisfied.
[PHONES] (33 Ω load)
• R (input side): -7.5 dBu ± 2 dBu
• L (nothing side): -72.0 dBu or less
6) For the L channel, perform the same operations as in Steps 4 and 5.
7) Unplug the stereo mini cable from the [AUX IN] jack.
If no problem is found, "AUX End" is shown on the LCD.