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1. P
recautions and Notices
1.1
SAFETY PRECAUTIONS
1) Observe all cautions and safety related notes located inside the display cabinet and on the display
chassis.
2)Operation of this display outside the cabinet or with the cover removed, may involves a shock harzard
from the display power supplies. Work on the display should not be attempted by anyone who is not
thoroughly familiar with precautions necessary when working on high voltage equipement.
3)Do not install, remove or handle the picture tube in any manner unless shatter-proof goggles are worn.
People not so equiped should be kept away while handling picture tube. Keep picture tube away from
body while handling.
1.2
Observe all cautionary and safety related notes located on the chassis, cabinet and display tube.
1.3
Operation of the monitor with the back cover removed presents a potential shock hazard. Only
personnel familiar with the precautions necessary for safe working on high voltage equipment should
attempt to carry out servicing.
1.4
Always wear shatter proof goggles when removing, installing or generally handing the picture tube.
People not so equipped should be kept at a safe distance when any such handing is being undertaken.
Do not handle the picture tube by the neck of deflection coil. Do not carry the picture tube resting against
the body.
1.5
The picture tube is designed and constructed to limit X-Radiation to a safe level during normal operation.
To maintain the required level of protection and safe operation, replacement tubes must be correctly
adjusted and any protective circuits must not defeated.
1.6
IMPORTANT-Safety Tests
After servicing, and before returning the monitor to the user, a thorough safety test must be carried out
to ensure there is no potential shock hazard to any operator(s) using the monitor.
All the following test must be performed. A monitor failing any of these tests should be rejected and have
the problem rectified.
1.7
A.C. Leakage Test
Remove the power sourse. Connent the monitor to the circuit as in figure 1 below. Switch the monitor
on/off switch to on. A reading of less than 3.5mA should obtained (ref. EN60950).
Equipment safety
Earth terminal
Equipment
Under test
Measuring instrument
Isolating
transformer
L
N
Fig. 1 Measurement of AC Leakage Current
ViewSonic Corporation
1
Confidential – Do Not Copy
A
9
0f+-1
Summary of Contents for A90f+ 1
Page 57: ...12 PCB Layout ViewSonic Corporation 54 Confidential Do Not Copy A90f 1...
Page 58: ...VIDEO PWB 0414 ViewSonic Corporation 55 Confidential Do Not Copy A90f 1...
Page 59: ...KEY CONTROL PWB 0488 ViewSonic Corporation 56 Confidential Do Not Copy A90f 1...
Page 60: ...MAIN BOARD 13 Schematic Diagrams ViewSonic Corporation 57 Confidential Do Not Copy A90f 1...
Page 61: ...VIDEO ViewSonic Corporation 58 Confidential Do Not Copy A90f 1...
Page 62: ...KEY CORTROL ViewSonic Corporation 59 Confidential Do Not Copy A90f 1...
Page 63: ...POWER SUPPLY CKT ViewSonic Corporation 60 Confidential Do Not Copy A90f 1...
Page 64: ...MCU CONTROL CKT ViewSonic Corporation 61 Confidential Do Not Copy A90f 1...
Page 65: ...Time Base DeflectionCKT ViewSonic Corporation 62 Confidential Do Not Copy A90f 1...
Page 66: ...H V DYNAMIC FOCUS CKT ViewSonic Corporation 63 Confidential Do Not Copy A90f 1...
Page 67: ...14 Exploded Diagram ViewSonic Corporation 64 Confidential Do Not Copy A90f 1...