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; Display: The Power Indicator Is Flashing - Yamaha R-S300 Service Manual

R-S300
● Display provided when Self-Diagnostic Function started
The display is as described below depending on the situation the last time the power to this unit is turned off.

1. When the power is turned off by usual operation:

"NO PROTECT" is displayed. Then the "1-1. FIRMWARE VERSION" menu 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 data of protection function which worked at the moment is displayed. Then "1-1. FIRMWARE VERSION" menu is
displayed in a few seconds.
Note: At that time if you reactivate the self-diagnostic function after turning off the power once by pressing the " "
(Power) key, "NO PROTECT" will be displayed because that situation is equal to "1. When the power is turned
off by usual operation:" described above.
However the protection function history is stored in a back-up IC with a backup. For details, refer to main menu "6.
PROTECTION HISTORY."
2-1. When there is a history of protection function due to excess current.

Display: The Power indicator is flashing.

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 protection function due to excess current works 1 time, 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
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.
20
After a few seconds
I P R O T E C T
Main menu display
V e r : D 0 5