Technical Cautions - Hitachi 36SDX88B Service Manual

TECHNICAL CAUTIONS
HV Protection Circuit Operation Checking
Hiah voltaqe limiter circuit operation check and over voltaae protection circuit operation check.
Adjustment Preparation
(1) Connect a high voltage voltmeter between CPT anode terminal (Anode cap side) and the ground as below.
(2) Set AC input voltage to 120+2V.
(3) Receive Hitachi circle pattern and set "Brightness" and "Contrast" to maximum. Adjust Screen VR so that Beam
Current is
le=l
.15&O. 1 mA. (The voltage of ABL terminal-CH22 both ends should be 12V or less).
CPT
Mgh voltage
voltmeter
(DC voltage dnrder)
CPT Ground
Wire
\ I
Use the voltmeter of rnput
impedence 1 Om ohm dr more
wth lndtcatlon to the 1st
decimal place.
Adjustment Procedure
(1) Check that the normal High Voltage is 30.0+0.2KV and +B Voltage is 22O+lV.
- -
(2) Connect jig B to the both end of RH38 and check that power turn off and standby mode is set.
(3) Disconnect the AC plug and remove jig B.
Less than
12v
(4) Turn the main power on. Check if power is supplied and high voltage rises.
10