The VFD's (lights) for the control dials have never worked

2 other complete control panels = no change in symptoms.
All other interior lights work and dim properly . 
Even the small red lights for defrost adjacent to the dials work and dim properly so presumably the unit is getting power and dimable (ruling out the fuses, light switches and dimmer i'd assume?).  

They used to work for 5 minutes then dim and maybe sometimes come back on occasionally.  But now they don't work at all.

The dealer is likely going to want to install a new control panel and are 3 months out to schedule...I find it hard to believe I've installed 3 bad panels, and I've sold two of them with no complaints from new owners. 

I'm also told I can't simply power the VFD's by grounding/powering them - they're too integrated and controlled and the diagnostics in the FSM are vague and don't specify anything about testing nonfunctional VFD's only. 

What would the professionals do?  

 

What is "VFD" standing for in this case?

If other illumination on the same panel works and dims then I would agree it's likely not wiring. 

I've seen plenty of cracked solder joints on circuit boards - especially ones with buttons and controls. 05-09 Legacy radio/HVAC panels are garbage and prone to this sort of problem. MAP light assemblies also. I would get out my handheld microscope and start looking for cracked joints that I can reflow. 

GD

7 hours ago, GeneralDisorder said:

What is "VFD" standing for in this case?

If other illumination on the same panel works and dims then I would agree it's likely not wiring. 

I've seen plenty of cracked solder joints on circuit boards - especially ones with buttons and controls. 05-09 Legacy radio/HVAC panels are garbage and prone to this sort of problem. MAP light assemblies also. I would get out my handheld microscope and start looking for cracked joints that I can reflow. 

GD

VFD - Vacuum Flourescent Display.  I’m told I can’t just easily power them directly like a bulb.  

Thanks, I’ll pull it out and do a closer inspection of the panel and ribbon.