25
8. Protection Block (HA-3 Chassis)
When D8014’s voltage reaches a critical level, IC8001 outputs a HIGH for as long as the TV is powered ON. The
HIGH passes through D8027 to trigger the Q6530/Q6532 latch that finally shuts off the TV set.
4. Surge Relay - If the secondary power supply (IC6501) came on but shut down in six seconds, it would seem as
though the TV’s AC relay had shut off the TV except that the AC relay remains energized.
This unlikely problem could happen if the primary power supply (IC6001 – A board) did not produce the 7Vdc
output used to energize the surge relay RY6502 or its contacts did not short out R6516. If the surge relay did not
energize after the TV was turned ON, C6595 would continue to charge. When this voltage reaches 0.6Vdc, latch
Q6526 and Q6529 would turn ON. This grounds the V sense voltage input to IC6501/pin 1, shutting down the
secondary power supply.
5. Shutdown Latch – Finally, an unstable standby voltage or a defect in the basic latch circuit (Q6530 and Q6532)
will also cause the TV to shut down without the standby light blinking. This last problem is rare.
Testing – If the TV relays turn ON but quickly turn back off with no standby light indication, use these flow charts
to determine which one of the five circuits is causing the shutdown:
AC
RELAY
Q6501
Q8009
OCP
SURGE
RELAY
RY6502,
PH503
LATCH
Q6526, Q6529,
Q6528,
Q6503
LATCH
Q6530,
Q6532
IC6501
SEC P.S
Q6506-7
T6501
C6595
100
R6527
PRIMARY P.S (A BD.)
D6530
R6516
AC
FROM
F BD.
Q6527
RELAY
DRIVER
V SENSE
UNREG 7V
FROM PRIM
P.S (A BD.)
R6526
R8043
200V
TO H.V.
CONV.
AC RELAY
FROM IC001-
MAIN MICRO (A
BD.)
+
D BD.
D8003
D8027
FROM
FBT
T8001
R6513-14
R6646
9/4/01
15TVP12 1333
FIGURE 8-3 - SHUTDOWN - NO INDICATION
IC8001
PROT.
LATCH
EXCESS
HV (FBT
VOLT.)
ABL (FBT
CURRENT)
D8014
Summary of Contents for KD-34XBR2 - 34" Hdtv Fd Trinitron Wega
Page 77: ...74 RA 5A Chassis Board Layout ...
Page 108: ...APPENDIX ...
