TroubleshootingProcedures
WFM90D and WFM91D ServiceManual 6-43
Fault Symptom Table
NOTE. Check the low-voltage power supplies (seeLow-Voltage Power Supply on
page 6--42)before proceedingwith the following procedure:
1. Disconnect the AC adapterfrom the instrument.
2. Remove any installedbatteries. See Batteries on page 6--28.
3. Remove the top cover.See Top Cover on page 6--5.
4. Remove the bottom cover.See Bottom Cover on page 6--31.
CAUTION. Toavoid breaking the circuit boards, do not tighten thecircuit board
vise too tightly.
5. Secure the instrumentcircuit boards in the circuit board vise.
6. Connect a 75% color bar test signal to the VIDEO IN connectorand connect
the VIDEO OUT connector to the picturemonitor.
7. Locate your faultsymptom in Table6--5 and use the indicated flowchartto
isolate the faulty module.
Table6- 5: Fault symptom table
Symptom Flowchart
Nodi splay after pressing the front panel ON button page6 --45
Graticule is good, but the Waveform display is distorted or not visible page6 --46
Graticule is good, but there is no Vector display page6 --47
Graticule is good, but the Audio display is distorted or not visible page6 --49
Nodi splay in the Picture display mode page6 --50
Badgrati cule and menu, but Picture display mode is good page6 --51
Displayall white page6 --52
Waveformdi splay mode sweep not triggered page6 --53
Vectordisplay unlocked page6 --54
Vectordisplay ji tter page6 --55
Distorted vectors in Vectordispl ay page6 --55
Control problem page6 --56
Menus horizontally unlocked in Picture display mode page6 --57