Yamaha RX-V681, Service Manual

Page: 35 / 170

35
RX-V681/RX-A760
RX-V681/RX-A7
60
●
Canceling Self-Diagnostic Function
1. Before canceling self-diagnostic function, execute setting for “ S3. FACTORY PRESET ” menu. (Memory initialization in-
hibited or Memory initialized).
* In order to keep the user memory preserved, be sure to select PRESET INHIBIT (Memory initialization inhibited).
2. Press the “ MAIN ZONE
z
” key to turn off the power.
●
Display provided when Self-Diagnostic Function started
The display is as described below depending on the situation when the power to this unit is turned off.
1. When the power is turned off by usual operation:
“
NO PROTECT
”
is displayed. Then
“
A1-1. DSP THROUGH
”
is displayed in a few seconds.
2. When the protection function worked to turn off the power:
The information of protection function which worked at that time is displayed. Then
“
A1-1. DSP THROUGH
”
is dis-
played in a few seconds.
Note:
At that time if you restart the self-diagnostic function after turning off the power once,
“
NO PROTECT
”
will be dis-
played. That is because that situation is equal to “ 1. When the power is turned off by usual operation: ” .
However history of the protection function is stored in memory as backup data. For details, refer to
“
P2. PRO-
TECTION HISTORY
”
menu.
2-1. When there is a history of protection function due to excess current.
Cause:
An excessive current flowed through the power amplifier.
Supplementary information:
As over current of the power amplifier is detected, check condition of each power 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.
Notes:
• Applying the power to this unit without correcting the abnormality can be dangerous and cause additional
circuit damage. To avoid this, if
“
I PROTECT
”
protection function works 1 time, the power will not turn on even
when the
“
MAIN ZONE
z
”
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.
NO PROTECT
A1-1
DSP THROUGH
After a few seconds
Opening message Main menu display
I PROTECT