1. DC-abnormality detection
DC detection is only enabled 2 seconds after power-on.
If there is a fault in the power amplifier or a high-level signal lower than 5 Hz is input,
the DC_DET port becomes “L”.
If the “L” is detected, the microprocessor will perform as following flow chart.
In the case of simultaneous detection with the overload protection circuit,
DC-abnormality detection is performed preferentially to overload detection.
If the speaker terminals are short-circuited or low-load driving is detected, the OL_DET port becomes “L”.
If the “L” is detected, the microprocessor will perform as following flow chart.
*A.MUTE : Audio mute command
↓
The abnormality continues for 3 seconds.
↓ Continues. ↓ Recovery
The power is shut off.
The program restarts.
↓
Power key not effective and POWER LED blinks (only for VSX-918V).
However, when the following keys are pushed so that the key input of a line and the service can
be carried out, power can be on.
1 TESTMODE ON (A55F+A55F)
2 When power off, push TUNE+ key + AUTO SURR/DIRECT key continuously 2sec.
(2: When a DC abnormality is detected and the power is shut off.)
Any other key input from front panel or remote control will not be detected.
2. Overload detection
↓
The abnormality continues for 3 seconds.
↓ Continues. ↓ Recovery
The power is shut off.
The power is shut off even if the
unit recovers.
When a DC abnormality is detected, A.MUTE* is turned
on, speaker relay is turned off, then
"AMP_ERR" flashes on the display.
When an overload is detected, A.MUTE* is turned on,
speaker relay is turned off, then
"OVERLOAD" flashes on the display.