Yamaha A-S201, Руководство по обслуживанию

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D C x x x L
P S x x x H
T A x x x H
Notes:
• Applying the power to this unit without correcting the abnormality can be dangerous and cause additional
circuit damage. To avoid this, if “PS” and “DC” protection function works 3 times consecutively, the power
will not turn on even when the “ ” (Power) key is pressed. In order to turn on the power again, disconnect the
power cable of this unit from the AC outlet once and then reconnect it again.
• The output transistors in each amplifier channel should be checked for damage before applying power to this unit.
• Amplifier current should be monitored by measuring DC voltage across the emitter resistors for each channel.
Cause: DC output of the power amplifier is abnormal.
Supplementary information: The protection function worked due to a DC voltage appearing at the speaker terminal.
A cause could be a defect in the amplifier.
Turning on the power without correcting the abnormality will cause the protection function to work in 3 seconds and the
power supply will be shut off.
2-2. When the protection function worked due to abnormal DC output.
xxx: A/D conversion value of voltage at the moment when the
protection function worked
(Reference voltage: 3.3 V = 255)
xxx: A/D conversion value of voltage at the moment when the
protection function worked
(Reference voltage: 3.3 V = 255)
xxx: A/D conversion value of voltage at the moment when the
protection function worked
(Reference voltage: 3.3 V = 255)
Cause: The voltage in the power supply section is abnormal.
Supplementary information: The protection function worked due to a defect or overload in the power supply.
Turning on the power without correcting the abnormality will cause the protection function to work in 1 seconds and the
power supply will be shut off.
2-3. When the protection function worked due to abnormal voltage in the power supply section.
Cause: The temperature of the heatsink is excessive.
Supplementary information: The protection function worked due to the temperature limit being exceeded. Causes could
be poor ventilation or a defect related to the thermal sensor.
Turning on the power without correcting the abnormality will cause the protection function to work in 1 seconds and the
power supply will be shut off.
2-4. When the protection function worked due to excessive heatsink temperature.
H: Displayed when the voltage is HIGHER than upper limit
L: Displayed when the voltage is LOWER than lower limit
H: Displayed when the voltage is HIGHER than upper limit
L: Displayed when the voltage is LOWER than lower limit
H: Displayed when the voltage is HIGHER than upper limit
L: Displayed when the voltage is LOWER than lower limit
21
A-S201
A
-S20
1