Technical Cautions - Hitachi C43-FD5000 Service Manual

TECHNICAL CAUTIONS

High Voltage limiter circuit operation check
1. Turn off TV and delete Resistor RH19（82KΩ） n the PWB .Add jig A to the RH19 position in the PWB，set 50 KΩ
VR fully clockwise(maximum resistance).
2. Set the AC input to 242V AC and turn on TV.
3. Confirm test pattern on PRT is a usable picture，then slowly adjust 50 KΩVR until the picture disappears and TV
shuts down.
4. When the limiter circuit is operating properly, High Voltage will be less than 36.8KV at 1.6mA when TV shuts down.
5. Turn off TV immediately after checking High Voltage limiter circuit operation. Unplug TV for one minute to reset
shutdown circuit. Remove the jig A，and then add resistor RH19（82KΩ）to the P.W.B.
33KΩ
50 KΩ VR
Deflection/Convergence P.W.B
RH17
FBT
RH19
Fig.2 High Voltage limiter circuit operation check
FBT
TH01
Connect Jig A to P.W.B between RH19.
33KΩ
6
50 KΩ VR
Jig A