Dimming the GTN 650 Display

[drgwentzel]

Hello pilots,

I have a relatively recent GTN 650 install and I cannot for the life of me figure out how to dim / adjust the display brightness.

The display appears to be at full brightness day or night. I cannot figure out how to set an auto dimming feature for nighttime operation (if one exists). In going into Settings and using the display brightness control does not change anything up or down. Can someone let me know what the secret handshake is for this device?

Gene

 

[bnt83]

Might be wired to a dimmer, or the automatic dimmer is incorrectly disabled. (auto dimmer is disabled when wired to a dimmer circuit)

 

[drgwentzel]

I think you hit the nail on the head here! I appreciate your response.

The only rationale I cannot figure out is why Garmin decided to make this so difficult. We're only talking about allowing the user to set auto dimming or to manually dim the display using its own internal commands. I just can't understand why Garmin wont allow the owner to make any changes. They seem to insist that it be taken to an avionics shop. Very frustrating!

Gene

 

[TrueCourse]

Like the previous post said, it sounds like it’s not a Garmin issue but an installation issue. That’s not Garmin’s fault.

 

[Hang 4]

There's a photocell that dims the unit based on external brightness. There is one setting in the system menu that lets you adjust it down or up. There is another setting that must be in the configuration menu. That sets whether or not the photocell controls dimming. Hold down the Home key when you start the unit to get to that menu. Don't change stuff in there unless you really know what you are doing. The dimming function is in that menu, not sure exactly where.
Here's what it looks like.