Z Board (Sound) Sos Detection - Panasonic TH-37PX50U Technical Manual

Z Board (Sound) SOS Detection

Figure 46
The 10V source of the Z board originates at the P board as 12Vdc. It is regulated to 10V
by the PB board. It then passes through the PA and H boards before entering the Z
board. The main 9V source of the PA board is also used on the Z board. It passes
through the H board and then enters the Z board. On the Z board, the transistor Q2323
monitors the 10 and 9 volts sources for a short. If a short is detected, a high output is
provided to the base of Q2324 resulting in a low output to pin 15 of IC4005. Twelve
blinks are generated when an abnormality is detected.
50