Yamaha HTR-6050, Service Manual

Page: 14 / 87

RX-V561/HTR-6050
14
NO PROTECTION
After a few seconds
DIAG menu display
1.ANLOG BYPASS
Opening message
When there is no protection history
When there is a history of protection function:
When there is a history of protection function due to excess current
PRI PRT:xxx
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:
AD value when the protection function is working
AD value when the protection function is working
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.
PRD PRT:xxx
• Starting DIAG
Press the “STANDBY/ON” key while simultaneously pressing those two keys of the main unit as indicated in the figure
below.
Turn on the power while pressing these keys.
Keys of main unit
• Canceling DIAG
1. Before canceling DIAG, execute setting for FACTORY PRESET of DIAG menu No.8 (Memory initialization inhibited
or Memory initialized).
* In order to keep the user memory stored, be sure to select PRESET INHIBITED (Memory initialization inhibited).
2. Turn off the power by pressing the “STANDBY/ON” key of the main unit.
• Display provided when DIAG started
On the FL display of the main unit, an opening message (including the protection history) appears for a few seconds
followed by the DIAG menu display (1. ANALOG BYPASS).
When there is a history of protection function due to abnormal voltage in the power supply section
PRV PRT:xxx
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.
If the power is turned on with the abnormality unsolved, the protection function works in about 1 second to
turn off the power.
AD value when the protection function is working
Note)
• Applying the power to the main unit without correcting the abnormality can be dangerous and cause addi-
tional 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 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 measuring across the emitter resistors for each channel.
• Starting DIAG in the protection cancel mode
If the protection function works and causes hindrance to trouble diagnosis, cancel the protection function as described
below, and it will be possible to enter the DIAG mode. (The protection functions other than the excess current detect
function will be disabled.)
Press the “STANDBY/ON” key while simultaneously pressing those two keys indicated in the figure above. At this time,
keep pressing those two keys for 3 seconds or longer.
In this mode, the [SLEEP] segment of the FL display of the main unit flashes to indicate that the mode is DIAG mode with
the protection functions disabled.
CAUTION!
Using this product with the protection function disabled may cause damage to the main unit. Use special care
for this point when using this mode.