I'm currently trying to fault find an issue with a Magnum S9 backlight. Its a very intermitant fault, sometime it will work fine all the time its on until a power cycle, and other times it will not work from cold; sometime just a small flash from the meter backlight will be the only indication that it wants to work.

My suspicion is it has something to do with the dimmer circuit which works accross all backlights for frequency counter, signal meter and channel number display.

I have all the schematics, which I'll post here.

Has anyone else has this issue, and being able to isolate the nature of the fault?