TroubleshootingProcedures
6-56 WFM90D and WFM91D Service Manual
Usethis proc edure when
thereis an instrum ent
controlproblem.
Yes
Replacethe Top Board first. These problems
canbe caused by either t he Topor Bottom
boards,and can only be det ermined by
replacingthese boards one at atime.
Domenu
selectionschange as t he
frontpanel buttons arepressed,
anddoes the graticule
appearok?
Dosome
frontpanel keys work,
andsome
donot?
Othercontrol problems include:
Theinstrument doesnot respond to f ront panel
keypresses a fter being turned on.
Alldisplay modes are bad or not visibleafter t he
instrumentis turnedon.
No
No
Replacethe Bott om board.
Removethe Key pad from Topboard and clean
thecontact s located under the carbon buttons.
Replacethe Keypad.
Yes
Figure6 -32: Flowchart for problems with the instr ument controls