2. Horizontal deflection circuit is defective.
The horizontal deflection
circuit is defective
Is the voltage on terminal
TP202=45V?
Is the power supply
circuit normal?
Is the pin1 waveform of
IC401 normal?
Is the pin28 waveform of
IC401 normal?
Is the pin26 waveform of
IC401 normal?
Is the waveform of Q402
"collector" normal?
Is the waveform of Q401
"BASE" normal?
Is the diode modulatic
circuit normal?
Is the voltage on terminal
TP201=75V?
Check power supply
circuit
Check H.sync input
Q402 is defective
Horizontal drive is
defective T402, Q401,
T401
Diode modulation circuit is
defictive C401, D401,
C413, C414, C415, C417,
Q409, C416
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
0.8Vp-p
45Vp-p
1.4Vp-p
12Vp-p
4.6Vp-p
fH
CRT is defictive
No
Check booster convertor
circuit Q202, Q204, Q205
Check IC401 pin26
normal?
39
ViewSonic Corporation
Co
nfidential - Do Not Copy
70f+SB-3
E
Summary of Contents for E70F - 17" CRT Display
Page 36: ...33 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 37: ...34 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 38: ...35 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 57: ...54 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 58: ...55 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 59: ...56 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 60: ...57 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 61: ...58 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 62: ...59 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 65: ...Model No E70f SB 3 62 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 66: ...Model No E70f SB 3 63 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 67: ...Model No E70f SB 3 64 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 68: ...Model No E70f SB 3 65 ViewSonic Corporation Confidential Do Not Copy 70f SB 3 E...
Page 77: ...11 PCB Layout Diagrams 74 ViewSonic Corporation Confidential Do Not Copy E70f SB 3...