Sony KV-32HS500 Training Manual page 40

4. DA-4 & DA-4X Protection Circuits
(Reference Figure 4-6)
Q2314 monitors the 5V dc level. If the dc level falls below 4.5V, Q2314 detects this error and the AC input is
disconnected.
RY6702 is used to remove the Inrush Current resistor from the AC input circuit after initial set turn-on. If the relay
failures to activate, AC input is disconnected.
IC9101, 9201 and 9301 on the CR/CB/CG boards are the cathode drive ICs. Each IC produces a separate IK
pulse directly proportional to the current in each cathode. The current in each cathode indicates the physical
condition of the cathode. Depending on the cathode condition, the set will either increase RGB drive to the
cathode or go into IK Protection mode.
+15V OVP monitors the 15V line for excessive voltage condition.
IC6502 is used to monitor both +135V OVP and OCP conditions.
Q528 on the A-board. If AC is not present at the input to the Standby 5V circuit, Q528 will activate the Latch and
shut down the TV.
IC8005 and Q8044 monitor the horizontal deflection operation.
IC8003 and V-DY(-) IC8003 is the vertical drive IC that drives the deflection yoke (DY). The low side of the
deflection yoke is monitored for proper vertical operation.
IC8006 and IC8007 monitor three separate circuits: Low HV, Excessive HV and FBT OCP.
38