Troubleshooting Procedures
WFM90D and WFM91D Service Manual
6- 45
Are the
sync
pulses
OK?
Replace the Top board.
Check for vertical and horizontal sync pulses:
(J9 is on Top Board.)
J9-18 = TTL level V-rate sync locked to the input signal.
J9-19 = TTL level H-rate sync locked to the input signal.
Remove the Display module and Backlight board. Connect
the AC Adapter and power up the instrument. Select
INT REF using the CONFIGURE menu.
No
Yes
Use this procedure when
the Waveform display
mode sweep is not
triggered.
Check the REF IN signal:
(J14 is on Bottom Board)
J14-9 = 1.2 Vpp, +1.3 VDC
blanking level.
Is the REF
IN signal
OK?
Yes
Replace the Bottom board.
No
Replace the
Input board.
Figure 6- 25: Flowchart for untriggered waveform display
Summary of Contents for WFM90D
Page 4: ......
Page 14: ...Service Safety Summary x WFM90D and WFM91D Service Manual...
Page 17: ...Specifications...
Page 18: ......
Page 29: ...Operating Information...
Page 30: ......
Page 44: ...Functional Overview 2 14 WFM90D and WFM91D Service Manual...
Page 57: ...Theory of Operation...
Page 58: ......
Page 62: ...Theory of Operation 3 4 WFM90D and WFM91D Service Manual...
Page 63: ...Performance Verification...
Page 64: ......
Page 82: ...Performance Verification Digital Section 4 18 WFM90D and WFM91D Service Manual...
Page 83: ...Adjustment Procedures...
Page 84: ......
Page 88: ...Adjustments 5 4 WFM90D and WFM91D Service Manual...
Page 98: ...Adjustment Procedures Digital Section 5 14 WFM90D and WFM91D Service Manual...
Page 99: ...Maintenance...
Page 100: ......
Page 130: ...Remove and Replace 6 30 WFM90D and WFM91D Service Manual...
Page 152: ...Troubleshooting Procedures 6 52 WFM90D and WFM91D Service Manual...
Page 153: ...Options...
Page 154: ......
Page 157: ...Replaceable Mechanical Parts...
Page 158: ......
Page 166: ...Replaceable Parts List 8 8 WFM90D and WFM91D Service Manual...
Page 167: ...Diagrams...
Page 168: ......
Page 170: ...Diagrams 9 2 WFM90D and WFM91D Service Manual...