AV-20420
AV-20421
1-30 (No.52111)
SECTION 4
TROUBLE SHOOTING
4.1 SELF CHECK FUNCTIONS
4.1.1
OUTLINE
This model has self check functions given below. When a malfunction has been detected, the POWER is turned off and the LED
flashes to inform of the failure . The malfunction is detected by the signal input state of the control line connected to the microcomputer.
4.1.2
SELF CHECK ITEMS
4.1.3
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 power is cut off
immediately.
At this time, the ON-TIMER LED flashes to inform of the
malfunction.
[ON-TIMER LED indication]
The ON-TIMER LED flashes at 0.5 seconds intervals.
Check item
Details of detection
Method of detection
State of malfunction
CRT NECK protector
[Also detected if the power
supply line output from the HVT
(High voltage Transformer) has
shorted with the ground.]
When the vertical circuit S-
correction capacitor C427 is
shorted, detect the potential
drop of the C427, and prevent
the burn damage to the CRT
NECK.
(Shorting of the power supply
output from the HVT to the
vertical circuit, and the small
signal power supply is also
detected.)
The microcomputer detects at
1 second intervals.
If NG is detected for more than
1 ms, a malfunction is
interpreted.
When a malfunction has been
detected, the POWER is turned
off. While the POWER is being
turned off , the power key of the
remote controller is not
operational until the power code
is taken out and put in again.
POWER
Supplied
POWER OFF
After about
5 seconds
Malfunction
is detected
Flashing
ON-TIMER LED
Содержание AV-20420, AV-20421
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