SELF-CHECK FUNCTIONS
1. Outline This model has self-check functions given below. When an abnormality has been detected, the SUB POWER is turned off and the ON TIMER LED flashes to inform of the failure. An abnormality is detected by the signal input state of the control line connected to the microcomputer.
2. Self-check items Check item Over-current protection Details of detection An over-current on the low B line is detected. Method of detection The main microcomputer detects the possible abnormality at 20msec. intervals and judges the results in every 24 time. Of the 24 times, if NG is detected more than 13 times, it is judged that there is an abnormality. State of abnormality When an abnormality has been detected, the SUB-POWER is turned off. While the SUBPOWER 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
CRT NECK protection
Operation of CRT NECK protection circuit
DITTO
3. Self-check indicating function When an abnormality has been detected at about 3 seconds after the power is turned on, the SUB POWER is turned off immediately and the ON TIMER LED flashes.
Power on
After about 3 seconds
Detection of an abnormality
Start of detection
Flashing ON TIMER LED
SUB-POWER OFF
[ Indication by the LED ] Item Over-current and CRT NECK protection LED flashing intervals At 0.24-second intervals