Display Provided When Self-Diagnostic Function Started; When The Power Is Turned Off By Usual Operation; When The Protection Function Worked To Turn Off The Power - Yamaha YHT-196 Service Manual

● 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 "1. ANALOG BYPAS" is displayed in a few seconds.
Opening message
N O P R O T E C T

2. When the protection function worked to turn off the power:

The information of protection function which worked at that time is displayed. Then "1.ANALOG BYPAS" is displayed 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
displayed. 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 a back-up IC. For details, refer to "21. PROTECTION
HISTORY" menu.
2-1. When the protection function worked 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.
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 " " (Power) key is pressed.
In order to turn on the power again, disconnect the power cable 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.
After a few seconds
P S P R T : x x x L
AD value when the protection function is working
HTR-2064/NS-B20/NS-C20/NS-SWP20
Main menu display
1 . A N A L O G B Y P A S
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