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AN-PR1100H

4 – 16

8

TO SUBWOOFER

TO POWER

AN-PR1100H

5 – 1

1. After the power is turned on, the microprocessor (ICM7) built in this

model continuously monitors the following defective operation. If
any abnormality occurs, all power is shut down except in the micro-
processor drive circuit.

1) An abnormal drop of each regulator output voltage.

(The protection circuit operates when the regulator output volt-
age is below 1.5 V.) The power is shut down immediately with
no display.

2) Defect of the cooling fan motor and the cooling fan drive circuit.

(Stoppage, etc.) The power is turned off after “FAN LOCK” is
displayed.

3) Over  voltage or reduced voltage of power supply.

The power is shut down immediately with no display when volt-
age is abnormal.

2. Failure detection conditions of the built-in microprocessor, check of

the detection line and solution.

Conditions

1) To detect failure according to voltage of the microprocessor

ICM7 pin 91.

2) Abnormal if pulse signals are not input into the pin 5 (FAN

LOCK) for more than 5 seconds.

3) Abnormal if the voltage of the pin 97 (+B CHECK) is lower than

1.2 V or higher than 3.0 V.

NOTE: If the microprocessor detects failures of 1), 2) and 3) 

above, it does not operate protectively when its PROTECT,
and +B CHECK detection lines are disconnected.
When these failures are caused by output short-circuit of each
regulator, components and PWB of the regulator may burn
out. If the cause is not clear, do not disconnect the detection
line.

(Even if any failure is detected, conduction is available for 0.5
second. You can check conduction by an oscilloscope, etc.
However, a tester is not available due to rapid rise and decay
of voltage.)

1. When output voltage of each regulator drops abnormally.

Connect the oscilloscope to the regulated output of the regulator
and power on the system. If the voltage is significantly lower than
that shown in the circuit diagram (approx. 1.5 V or less), the regula-
tor itself and the destination circuit are suspected.

AN-PR1100H

5 – 2

If any failure is detected, STANDBY LED blinks red after power off
(see Fig. 1 below). You can identify the failure state by checking
which LED output number from the frame head is blinking 4 times 
each for 2 seconds.

Fig. 1 shows the LED output No. 2. is blinking due to failure.

Normally, LED light up for 2 seconds and light off for 1 second on a
3-second cycle (6 times from No. 1 to No. 6). For No.7, LED light off
for 3 seconds, showing the frame end (for recognition of the frame
head).

In No. 2, LED blinks alternately at shorter intervals than usual for fail-
ure identification. For failure status, refer to the appendix, “STAND-BY 
LED Error Message”.

1. SYS-PROTECT detection: To detect failure of the power supply cir-

cuit (except the 1.8 V power supply circuit).

2. B_CHECK detection: To check timing at power ON/OFF and detect

over voltage and reduced voltage of the primary AC power after the
power is turned on.

3. AVCK detection: To detect failure of the 1.8 V power supply circuit

(AVCK1 and AVCK2).

4. AMP_SW_PROT detection: To detect failure in the subwoofer AMP.

3sec

2sec

500m

500m

500m

500m

3sec

1 frame

2sec

3sec

2sec

3sec

2sec

3sec

2sec

3sec

No.1

LED output

Power OFF

LED output

Red ON

No.2

Alternate blinking for
failure detection

As shown in Fig. 1, LED alternately blinks due to failure on a
500-msec cycle with duty of 50%. 

No.3

No.6

No.7

No.1

1

SYS-PROTECT detection

Immediate power shut-down; Identification No.1 blinking

2

B_CHECK detection

Immediate power shut-down; Identification No.2 blinking in case of over voltage

No blinking in case of reduced voltage

3

AVCK detection

Immediate power shut-down; Identification No.3 blinking

4

AMP_SW_PROT detection

Immediate power shut-down; Identification No.6 blinking

AN-PR1100H

5 – 3

(at no signal)