ViewSonic Corporation E90fB-4
2
Confidential-Do Not Copy
combination 1500 ohm resistor and 0.15uF capacitor.
5-4 Move the resistor connection to each exposed metallic part and measure the voltage.
5-5 Reverse the polarity of the AC plug in the AC outlet and repeat the above measurement.
5-6 Voltage measured must not exceed 7.5 volt RMS, from any exposed metallic part to ground A leakage current
tester may be used in the above hot check, in which case any current measured must not exceed 5.0 milliamp. In
the case of a measurement exceeding the 5.0 milliamp value, a rework is required to eliminate the chance of shock
hazard.
Note
：
High voltage is present when this CRT display is operating. Always discharge the anode of the picture tube to the
display chassis to prevent shock hazard.
AC VOLTMETER
Fig. 1
6. IMPLOSION PROTECTION
Picture tubes are equipped with an integral implosion protection system, but care should be taken to avoid damage and
scratching during installation. Use only Panasonic replacement picture tubes.
7. X-RADIATION
WARNING
：
The only potential source of X-Radiation is the picture tube. However when the high voltage circuit is
operating properly there is no possibility of X-Radiation problem. The basic precaution which must be exercised is to
keep the high voltage at the following factory-recommended level.
Note
It is important to use an accurate periodically calibrated high voltage meter.
7-1 The procedure for adjusting high voltage is shown on page 12.
7-2 If can not be adjust 25.0 KV at immediate service is required to prevent the possibility of premature
component failure.
7-3 To prevent X-Radiation possibility it is essential to use the specified picture tube
There are special components used in this CRT displays which are
important for safety. These parts are identified by the international
symbol
on the schematic diagram and on the replacement parts
list. It is essential that these critical parts should be replaced with
manufacture’s specified parts to prevent X-RADIATION, shock, fire,
or other hazards. Do not modify the original design or this will void
the original parts and labor guarantee.
！
IMPORTANT SAFETY NOTICE
Summary of Contents for PerfectFlat E90fB-4
Page 46: ...ViewSonic Corporation E90fB 4 43 Confidential Do Not Copy 9 BLOCK DIAGRAM...
Page 48: ...ViewSonic Corporation E90fB 4 45 Confidential Do Not Copy SAA4849...
Page 52: ...ViewSonic Corporation E90fB 4 49 Confidential Do Not Copy...
Page 58: ...ViewSonic Corporation E90fB 4 55 Confidential Do Not Copy 11 PCB LAYOUT 11 1 MAIN PCB LAYOUT...
Page 59: ...ViewSonic Corporation E90fB 4 56 Confidential Do Not Copy 11 2 CRT BOARD LAYOUT...
