My screen went blank after I restored factory defaults on my WFM601. What happened?

My screen went blank after I restored factory defaults on my WFM601. What happened?

What usually causes this is that on older instruments, the CRT has faded over time and operators have periodically adjusted the CRTbrightness to compensate for this. Later, when the factory preset is recalled, it assumes theCRT is brand new and sets the intensity to the default level which due to aging is now too low to be visible on the screen. The way to correct this is to turn the brightness back up on the instrument. To do this when you can't see the screen simply turn the instrument on, press the CRT button (a small LED should light up next to the letters CRTto let you know you are now in this menu). Now you can use the 4th bezel knob from the left (2nd from the right) to adjust the display brightness. Turn the knob clockwise to increase brightness or counter-clockwise to reduce the brightness. You can use the top bezel button to switch to the readout setting and again turn the 4th knob clockwise to increase this value until text is visible on the screen again.