- This unit has self-diagnostic functions that are intended for inspection, measurement and location of faulty point.
- There are 26 main menu items, each of which has sub-menu items.
- Listed in the table below are main menu items and sub-menu items.
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STARTING SELF DIAGNOSTIC FUNCTION
- If the protection function works and causes hindrance to trouble shoot, cancel the protection function as described below, and it will be possible to enter the self-diagnostic function mode. (The protection functions other than the excess current detect function will be disabled.)
- While pressing the “TONE CONTROL” and “STRAIGHT” keys as shown in the figure above, press the “” (Power) key to turn on the power and keep pressing those 2 keys and the “ ” (Power) key for 3 seconds or longer.
- The self-diagnostic function mode is activated with the protection functions disabled.
- In this mode, the “SLEEP” segment of the FL display of this unit flashes to indicate that the mode is self-diagnostic function mode with the protection functions disabled.
Canceling Self-Diagnostic Function
- Before canceling self-diagnostic function, execute setting for FACTORY PRESET of main menu No.24. (Memory initialization inhibited or Memory initialized). # In order to keep the user memory preserved, be sure to select PRESET INHIBITED (Memory initialization inhibited).
- Press the “ ” (Power) key of this unit to turn off the power.
Display provided when Self-Diagnostic Function started
- The display is as described below depending on the situation when the last time the power to this unit is turned off.
- When the power is turned off normally:
- The FL display of this unit displays “NO PROTECT” then the main menu (sub-menu “1. ANALOG BYPAS” of main menu 1 BYPASS) a few seconds later.
When the protection function worked to turn off the power:
- The FL display of this unit displays the data of protection function which worked at that time then the main menu (sub-menu “1. ANALOG BYPAS” of main menu 1 BYPASS) a few seconds later.
- Note: When 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 21 PROTECTION HISTORY.
When the protection function worked due to excess current.
NO PROTECT è 1.ANALOG BYPAS
Supplementary information: As current of the power amplifier is detected, checking the current can identify the abnormal channel 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 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.When the protection function worked due to a short between speaker terminals.
I PROTECT
Cause:The line between speaker terminals is shorted.
Supplementary information:As the excess current is detected after operation of the speaker relay, the shorted speaker terminal and the connected speaker can be identified.
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 the protection function worked due to abnormal DC output.
DC PRT:xxxH [AD value when the protection function is working]
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.
Turning on the power without correcting the abnormality will cause the protection function to work in 3 seconds and the power supply will be shut off.
When the protection function worked due to abnormal voltage in the power supply section.
PRV PRT:xxxL [AD value when the protection function is working]
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.
Turning on the power without correcting the abnormality will cause the protection function to work in 1 seconds and the power supply will be shut off.