Denon AVR-E400 Service Manual page 46

3.5. Errors checking mode (Displaying the protection history)
3.5.1. Operation specifications
Error mode (Displaying the protection history):
When the set is started up in this mode, the error information is displayed.
3.5.2. About the display on the FL display
When the "STATUS" button is pressed after the error (protection history display) mode is set, a history like the one shown
below is displayed, depending on the conditions.
(1) Normal (when there has been no protection incident)
FLD
N O P R O T E C T
(2) For ASO (when the last protection incident was ASO protection)
FLD
P R T : A S O
Cause: The line between speaker terminals is shorted, or speakers with impedance of less than the rated value.
Supplementary information:
If the power is turned on without correcting the abnormality, the protection function will work about 5 seconds later and the
power supply will be shut off.
(3) For DC (when the last protection incident was DC protection)
FLD
P R T : D C
Cause: DC output of the power amplifier is abnormal.
If the power is turned on without correcting the abnormality, the protection function will work about 5 seconds later and the
power supply will be shut off.
(4) For THERMAL (when the last protection incident was THERMAL(A) or THERMAL(B) protection)
FLD
P R T : T H E R M A L
FLD
P R T : T H E R M A L
Cause: The temperature of the heat sink is excessive.
If the power is turned on without correcting the abnormality, the protection function will work about 5 seconds later and the
power supply will be shut off.
b Additional causes of protection can be due to loose connections, associated components, Microprocessor, etc.
When the "STATUS" button is pressed again after the protection history as shown above is displayed, the normal display
reappears.
As the excess current is detected after operation of the speaker relay, a short on the
speaker terminal and the connected speaker can be identified.
A
B
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