Panasonic Generation Plasma Display Television, Техническое руководство

Страница: 64 / 98

DRV_RST SOS
The DRV RST circuit of the D board is used to monitor the physical connection of the D board to the C
board. DRV RST input to IC9500 and IC9003 must be high for the unit to operate. The D board
provides the 5V source needed to power the C boards. On the C2 board, the 5V is routed back to the D
board via connector C20/C10, C11/D31 to activate the 5V SENSE circuit. A voltage divider consisting of
R9369 and R9371 develops a voltage drop that causes the collector of transistor Q9301 to become low.
As a result, the base voltage of Q9302 also becomes low causing its collector to go high. The output
voltage is applied to IC9500 and IC9003 as DVR RST.
When the 5V SENSE circuit does not detect 5V from the C2 board, the DVR RST output becomes low.
The unit goes into shutdown and the power LED blinks 12 times.
When troubleshooting 5 blinks SOS, isolating the C board and the panel may be necessary. To avoid
having the power LED blink 12 times after disconnecting either D31/C11 or D32/C21, test point TP9010
should be shorted to ground.
Test Point TP9200 is the ideal location to check for DRV RST.
64