Table of Contents
WFM 90 and WFM 91 Service Manual iii
List of Figures
Figure 2–1: Installing the viewing hood 2–2. . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–2: Installing the desk stand 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–3: Instrument front panel 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–4: Instrument side panels 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–5: On-screen readout messages 2–9. . . . . . . . . . . . . . . . . . . . . . .
Figure 3–1: Simplified block diagram 3–3. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 4–1: –3 dB marks on the vector graticule 4–12. . . . . . . . . . . . . . . . .
Figure 5–1: NTSC graticule showing the vector gain adjustment 5–9. . .
Figure 6–1: Removing the top cover 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–2: Installing the LCD display cable 6–9. . . . . . . . . . . . . . . . . . . .
Figure 6–3: Installing the LCD display 6–11. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–4: Installing the keypad 6–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–5: Installing the Top board shield 6–15. . . . . . . . . . . . . . . . . . . . .
Figure 6–6: Installing the Bottom board 6–17. . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–7: Installing the battery cover 6–19. . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–8: Removal and replacement of the turnlock stud 6–20. . . . . . . .
Figure 6–9: Removing the NiCad battery pack 6–22. . . . . . . . . . . . . . . . . .
Figure 6–10: Installed polarity of alkaline batteries 6–23. . . . . . . . . . . . . .
Figure 6–11: Battery contact installation alignment 6–25. . . . . . . . . . . . . .
Figure 6–12: Battery power-wire and turnlock stud receptacle
installation 6–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–13: Battery orientation marker position 6–28. . . . . . . . . . . . . . . .
Figure 6–14: Installing the EMI suppressor 6–29. . . . . . . . . . . . . . . . . . . . .
Figure 6–15: Testing the battery charging circuit – WFM90 SN B011362
and below; WFM 91 SN B010470 and below 6–32. . . . . . . . . . . . . . . . .
Figure 6–16: Testing the battery charging circuit – WFM90 SN B011363
and above; WFM 91 SN B010471 and above 6–33. . . . . . . . . . . . . . . . .
Figure 6–17: Flowchart for no display 6–37. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6–18: Flowchart for distorted waveform display 6–38. . . . . . . . . . .
Figure 6–19: Flowchart for no vector display 6–39. . . . . . . . . . . . . . . . . . . .
Figure 6–20: Flowchart for bad audio display 6–40. . . . . . . . . . . . . . . . . . .
Figure 6–21: Flowchart for no picture display 6–41. . . . . . . . . . . . . . . . . . .
Figure 6–22: Flowchart for bad graticules and menus 6–42. . . . . . . . . . . .