Sos Detect Circuit - Panasonic TC-P50VT20 Technical Manual

Protection circuits are incorporated in the unit to prevent the failure of a single circuit or component
from creating catastrophic damage.
A shutdown condition occurs when a there is an over voltage, a short or a drop in any of the voltage
lines. Also when the fans are drawing more current than normal the shutdown circuit is triggered.
Normally the CPU of the D board and the CPU of the A board detect when a shutdown condition has
been triggered.
When an abnormality has occurred, the unit protection circuit operates and the TV is reset to the
stand-by mode. At this time, the defective block can be identified by the number of blinks of the
POWER LED on the front of the unit.
IC9003 of the D board detects conditions that make the power LED blinks 2, 3, 4, 5, 6, 7, 8, or 9 times.
IC 1100 on the A board detects conditions that make the power LED blinks 10, 11, and 12 times.

SOS Detect Circuit

Slide 77 Slide 77