SUB-CPU (IC800) is programmed so the set will go to stand-
by mode when there is circuit failure as described below.
(Refer to"Block Diagram Power Lines".)
This unit is equipped with a Power Failure Detector function
included in the SUB-CPU which checks for an abnormal
condition in the chassis power supplies.
If, while the power is on, a failure is caused by any of the
following that results in a low voltage supply, the SUB-CPU
will turn the unit off in 1.5 seconds to prevent further
Failure within the power supply circuits.
A short circuit in the load side from the supply.
Power Failure: Detected voltage failure for circuit.
(Connected to IC800 pin 48 and pin 23.)
(Normal: High; Failure: Low)
If, while the power is off, the power is switched on and any
of these failures remains uncorrected, the SUB-CPU will
shut off the power within three seconds.
POWER FAILURE CIRCUIT
Check the following if the unit is turned off by the power
1. Disconnect the AC power cord (120V AC line) for a short
2. Connect a DC Voltmeter to the circuits shown below.
3. Press the Power key and check for the proper voltage
4. If any of these voltages is low, the power failure detec-
tor should turn the unit off within three seconds.
5. Check all circuits shown below.
Note: If power failure is detected 3 times in 15 minutes,
the set will enter the standby mode and cannot be
switched On.To reset the operating programs of the
SUB-CPU it is necessary to disconnect the AC cord
for a short time.
Power Fail 1
Power Fail 2
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