Yamaha RX-V671 Service Manual page 32

RX-V671/HTR-6064/RX-A710
2-2. When the protection function worked due to abnormal DC output.
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 5 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 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.
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 "MAIN ZONE " key is pressed. In order to turn on the power again, start up the self-
diagnostic function.
• 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.
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AD conversion value when the protection function is working
AD conversion value when the protection function is working