Yamaha RX-V363 - AV Receiver, Service Manual

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RX-V363/HTR-6130
23
RX-V363/HTR-6130
When there is a history of protection function due to excess current
Cause: An excessive current flowed through the power amplifier.
Supplementary information:
As current of the power amplifier is detected, the abnormal channel can be identified by checking the current
detect transistor.
Turning on the power without correcting the abnormality will cause the protection function to work immediately
and the power supply will instantly be shut off.
When there is no history of protection function:
NO PROTECTION
After a few seconds
1.ANLOG BYPASS
When there is no protection history
Note)
• Applying the power to this unit without correcting the abnormality can be dangerous and cause additional
circuit damage. To avoid this, if “PRI” and “PRD” protection function has been activated 3 times continuously,
the power will not turn on even when the “STANDBY/ON” 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.
PRI PRT:xxx
AD value when the protection function is working
AD value when the protection function is working
PRD PRT:xxx
When there is a history of protection function 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.
If the power is turned on with the abnormality unsolved, the protection function works in about 3 seconds to turn
off the power.