Troubleshooting - JVC AV-29L6SU Service Manual

5.1 SELF CHECK FUNCTIONS
5.1.1 OUTLINE
These models have self-check functions given below. When an abnormality has been detected, the SUB POWER is turned off and
POWER LED is blinking. An abnormality is detected by the signal input state of the control line connected to the microcomputer.
5.1.2 SELF CHECK ITEMS
Check item
Low B short protection
CRT neck broken protection Operation of CRT neck broken
X-ray protection
5.1.3 SELF CHECK INDICATING FUNCTION
When an abnormality has been detected at about 5 seconds
after the power is turned on, the SUB POWER is turned off
immediately and the POWER LED begins blinking.
1-28 (No.YA366)
SECTION 5

TROUBLESHOOTING

Details of detection
A short on the low B (1.8V,
3.3V) line is detected.
protection circuit.
(Vertical amplitude is detected.)
The rise of a high voltage value
is detected.
Method of detection
The protect port on
microcomputer (100pin) is always
monitored at 10msec intervals. If
an abnormality is detected 75 times
successively, it is judged that there
is an abnormality.
DITTO
DITTO
Power on
State of abnormality
the When an abnormality has detected,
the SUB POWER is turned off and
POWER LED lis blinking. While the
SUB POWER is being turned off,
the POWER key on the remote
control unit is not operational until
the power cord is taken out and put
in again.
DITTO
DITTO
After about
Detection of
5 seconds
an abnormality
Blinking the POWER LED
Start of
detection
SUB-POWER OFF