Read Sony CMT-C7NT / SA-C7 Service Manual online
2
SA-C7
SERVICE NOTE
[When bringing in the equipment for service]
The notice is shown on both Warranty Card and Repair Service column of operation manual, telling to bringing in both
of the equipment (HCD-C7NT) and speaker system (SA-C7) together to service station when service (repair) is needed.
The notice is shown on both Warranty Card and Repair Service column of operation manual, telling to bringing in both
of the equipment (HCD-C7NT) and speaker system (SA-C7) together to service station when service (repair) is needed.
[How to check speaker only]
When only speaker is brought in for service, check its operations by supplying both the power and the signal to the AMP
board of the speaker as shown below.
When only speaker is brought in for service, check its operations by supplying both the power and the signal to the AMP
board of the speaker as shown below.
Check method :
1.Perform connection as shown below.
1.Perform connection as shown below.
•
DC regulated power supply 1 (+5 V)
It functions to turn on the speaker relay driver.
•
DC regulated power supply 2 (±20 V)
It is desirable to use the DC regulated power supply of the dual tracking type that can supply its output voltages in two
polarities of positive and negative polarities. However, the two units of the DC regulated power supply that supplies
only a single output voltage can also be used. (See the figure below.)
polarities of positive and negative polarities. However, the two units of the DC regulated power supply that supplies
only a single output voltage can also be used. (See the figure below.)
•
Audio signal generator
Output frequency : 1 kHz
Output voltage
Output frequency : 1 kHz
Output voltage
: 100mV p-p or less
Output impedance : 600
Ω
2.Turn on the main power of the DC regulated power supply 2.
Then turn on the main power of the DC regulated power supply 1 (+ 5 V).
After that, input the output signal of the audio signal generator as shown.
After that, input the output signal of the audio signal generator as shown.
3.Check that the LED (D831, D832 (BLUE)) turns on and the audio signal can be heard from the speaker.
Notes :
1
1
For the speaker cord, disconnect it from the speaker or leave it open.
2
Be careful not to apply an excessive input audio signal to the speaker.
3
If the power voltage is less than +/- 14 V, the speaker relay will not be activated.
[Caution when removing the front panel]
The special screwdriver (Sony part code No. 7-640-005-55) of star type (six star type) is required to remove the front
panel.
The special screwdriver (Sony part code No. 7-640-005-55) of star type (six star type) is required to remove the front
panel.
9
8
7
6
5
4
3
2
1
DC regulated
power supply
2
Audio signal
generator
RELAY
SP-GND
+B
POWER-GND
-B
SHIELD GND
PRE-SIGNAL
CN801
AMP board
LED (BLUE)
Speaker
DC regulated
power supply
1
+5V
GND
GND
+
+
+20V
-20V
AUDIO SIGNAL
COM
-
-
DC regulated
power supply
power supply
+
-
DC regulated
power supply
power supply
+
-
7
6
5
4
3
+B
POWER-GND
-B
CN801
+20V
-20V
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