JVC AV-T2122 Service Manual page 21

SELF CHECK FUNCTIONS
1. Outline
This model includes protector functions for Over-current, X-ray and CRT NECK which cutoff the sub-power in the event of a malfunction and
inform of the malfunction by flashing POWER/ON TIMER LED.
The malfunction is detected according to the state of the control line input connected to the main CPU.
2. Self check items
Check item
Over-current protector
X-ray protector
CRT NECK protector
3. Self check indicating function
The self check function begins detection about 5
seconds after power is supplied.
In the event a malfunction is detected, the sub-power is
cutoff immediately.
At this time, the POWER/ON TIMER LED flashes to
inform of the malfunction.
Item
OCP/X-ray
NECK
Detected contents
Operation of over-current
protection circuit
Operation of X-ray protection
circuit
When the vertical circuit S-
correction capacitor C413 is
shorted, detect the potential
drop of the C413, and prevent
the burn damage to the CRT
NECK.
POWER
supplied
LED flashing intervals
Red and green LED flash alternately at
0.5 second intervals
Red and green LED flash alternately at
1.0 second intervals
No.51866
Detection method
The main CPU detects
1second intervals.
If NG is detected for more than
1ms, a malfunction is interpreted
The main CPU detects
1second intervals.
If NG is detected for more than
1ms, a malfunction is interpreted
The main CPU detects
1second intervals.
If NG is detected for more than
1ms, a malfunction is interpreted
About 5 seconds
after
Detection
start
AV-T2122
Abnormality state
at During an abnormality the sub-
power is cutoff. The remote
controller power key operation is
not recognized and sub-power
off is maintained until the power
cord is unplugged and
reinserted.
at During an abnormality the sub-
power is cutoff. The remote
controller power key operation is
not recognized and sub-power
off is maintained until the power
cord is unplugged
reinserted.
at During an abnormality the sub-
power is cutoff. The remote
controller power key operation is
not recognized and sub-power
off is maintained until the power
cord is unplugged
reinserted.
Malfuction is
detected
SUB-POWER OFF
Flashing
POWER /
ON TIMER LED
Priority of detection
1
2
and
and
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