Yamaha RX-V461 Service Manual page 8

When there is no history of protection function:
Opening message /
When there is no protection history
NO PROTECTION
When there is a history of protection function:
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 func-
tion to work immediately and the power sup-
ply will instantly be shut off.
Note)
• Applying the power to the main unit without cor-
recting the abnormality can be dangerous and
cause additional circuit damage. To avoid this, if
"PRI" and "PRD" protection function has been ac-
tivated 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, dis-
connect the power cable of the main 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 of the main unit.
• Amplifier current should be monitored by measur-
ing across the emitter resistors for each channel.
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.
DIAG menu display /
After a few seconds /
PRI PRT:xxx
AD value when the protection function is working
PRD PRT:xxx
AD value when the protection function is working
RX-V461/HTR-6040/DSP-AX461
1.ANLOG BYPASS
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