Protection Block (Ha-3 Chassis) - Sony KD-34XBR2 Training Manual

Refer to Figure 8-1 for the following overview of the protection circuits. When a failure occurs, this TV will protect
the remainder of its circuitry in one of the following ways:
•
TV shutdown (AC relay is turned off);
•
TV Latched OFF (AC relay is held off); or
•
A dark picture (no RGB signal to the CRT cathodes).
When Main Micro IC001 places the TV in a protective state, IC001 also indicates the cause by blinking the
Standby LED a number of times, pauses, and then repeats the same count.
NUMBER OF TIMES
X
D BD.
3X
0X
EXCESS
HV
0X
ABL
Q8008
0X
+200V POWER OFF
OCP
AC RELAY
POWER
ON/OFF
There are seven protected areas summarized in Chart 8-1. Chart 1 also lists the signal that triggered the protec-
tion. If no signal triggered the protection, suspect Micro IC001 on the B board and the latch transistors (Q6522/
Q6530) on the D board of causing the TV shutdown. Figure 8-2 shows the location of Chart 8-1' s protection
signal checkpoints.

Protection Block (HA-3 Chassis)

THE STANDBY
LIGHT BLINKS
OVP
CN001/
+135V
CN3020
OVP
7
2X
OVP
+135V
OCP
8
CN6506/
CN3171
0X
LATCH
CN6504/
CN3170
1
FIGURE 8-1 - PROTECTION BLOCK
IC001 MAIN MICRO
S
OCP
DATA
A25 C25 C24 C26
Q6.5V
OCP/
OVP
OCP
6X
AC
RELAY
23
8. Protection Block (HA-3 Chassis)
STANDBY LED
SCLK
B19 A20
CN002/
CN3022
8
CN3101/
IC3101
CN9001
Y/C CRT
7
DRIVE
8
CN3103/
CN5505
A BD.
20TVP12 1338
B BD.
C BD.
5X
IK
PULSES
V LOSS
4X
+135V
OCP
7X
(H.OUT)
D BD.
9/4/01