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SECTION 3
LED Green
No video
Check if Q121 Drain
waveform is normal
YES
NO
Check SMPS DC O/P
(SECTION 1)
NO
Check I101 pin1 =3.6V approx. ,
pin2 = 2.5V approx.
NO
Check OVP CKT setting
build by Q114, 115, 116
Check 82V at pin2 of
FBT(T101)
YES
Check CRT R, G, B
cathode and G1
Is the voltage 6.3V at
heater?
YES
Check P904, P903
connection
YES
Check G2 (P906)
connection
YES
ViewSonic Corporation
30
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...