Yamaha DG60-112 Service Manual page 13

When fully turning the check volume knob counterclockwise, the A ch LED (CN5–2 pin) will light; when fully
turning it clockwise, the B ch LED (CN5–3) will light. If the volume is no good, both the A ch and B ch LEDs
(CN5–2, 3 pin) will light to indicate the error.
Each press of the switch (SW2) will proceed to the next volume check after lighting both the A ch and B ch LEDs.
Press the switch (SW2) after finishing the volume checks to proceed to the next Sound Check. When cancelling a
test during a check, hold down on the switch (SW2) for a few seconds. The A ch and B ch LEDs will then go out, re-
light, then the test will be cancelled.
3. Sound Check (Power Amplifier Adjustment)
3-1 Idling Adjustment
1) Before turning the [POWER] switch on, set the Idling Adjustment Volume (VR201, 1 k ohms) on the MAIN
circuit board at minimum.
2) Press the channel select switch and select the B ch.
3) Connect an 8 ohm load between the speaker terminals BT202 and BT203.
4) Set the B ch MASTER volume at minimum.
5) After turning the POWER switch on, adjust the Idling Adjustment Volume (VR201) to set the voltage of the
terminals of the CN204 or R252 at 5 mV +/- 1 mV.
3-2 Sound Check
This Sound Check is performed by using a signal that goes through the following circuits: the analog circuit, the
A/D converter, the DSP-3 and the D/A converter.
This check should be performed after the VOLUME check has finished and when both the A ch and B ch LEDs
(CN5–2, 3) are lit.
Items
Input Sensitivity
1
(High)
Input Sensitivity
2
(Low)
RETURN Level
3
(0 dB)
RETURN Level
4
(-20 dB)
SEND Level
5
(0 dB)
SEND Level
6
(-20 dB)
Frequency Response
7
(HIGH IN)
8 Remain Noise
Sensitivity of LED for Input
9
Level
10 Output
* 0 dBm = 0.775 V
When Sound Check is completed, turn the [POWER] switch off to quit the self check mode.
R252
0.33
CN204 T·P
1 kHz, -20 dBm, 8 ohms load
1 kHz, -10 dBm, 8 ohms load
1 kHz, -2 dBm,
8ohms load (SW1: 0 dB)
1 kHz, -22 dBm,
8ohms load (SW1: 20 dB)
1 kHz, -20 dBm,
100 kohms SEND load (SW1: 0 dB)
1 kHz, -20 dBm,
100 kohms LINE OUT load
-30 dBm Input, 1 kHz standard
SP Output Terminals: 8 ohms load
TRIM, OUTPUT
VR MIN IHF A net
1 kHz, -10 dBm,
8 ohms load
RETURN, 10 %THD
5W
T·P
Conditions
DG60-112
Responses (standards)
+25 dBm +/-2 dB
+25 dBm +/-2 dB
+28 dBm +/-2 dB
+28 dBm +/-2 dB
-3 dBm +/-2 dB
+2 dBm +/-2 dB
100 Hz: -0.5 +/-1 dB
10 kHz: -0.5 +/-1 dB
Less than -60 dBm
-10 dBm Input: no light
+50 dBm Input: lit
More than +28 dBm
(50 W) 8 ohms load
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