D 180 screen is too dark to read

[jaba-who]

My apologies if this has been covered elsewhere but my search turned up a blank.

I have a D180 attached to an AP74 and two AP servos. I have just reinstalled them after a cabin refurbish and now the screen is really dark. All attempts to make it brighter ( less dim) using the on screen commands don't seem to make any difference.

But it's more complex.
If I turn the devices on while the aircraft is in a dark hanger it turns on fairly bright. Not as bright as it used to be but still bright and easily readable.
If I start it up while the aircraft is out in the sun the screen is so dark the first thought is that it is not on at all. But after a few minutes it gets just visible enough to read with difficulty. Certainly not enough to use in flight.

If I start it up in the hangar it comes on bright and then if I move the aircraft (with the d 180 still on on and reasonably bright) it stays bright as I move it into the sun. Then if I turn it off and back on it's now stays bright.

The internal battery is fully charged (16.2 v), the aircraft battery is full (12.7 v), the data displayed on the screen and all the sensors etc seem to be working and correct. The firmware is the latest version ( although it's from a few years back now.)

Something that was happening for a while was that the screen was dimming intermittently in time with the roughly one second frequency clicking the device makes normally when running. But the internal and external batteries were low and that seems to have stopped after I had them both fully charged.

Also with all the sensors installed if I disconnect the main power earth wire the device still runs normally - presumably earthing through a sensor ground as an alternate earth. Is that ok or should it be only running to earth through the main earth wire. This is potentially an issue ( even if it's ok) as it means it's bypassing the circuit breaker which I have in the earth line.

 

[jakej]

DS will probably chime in here but my guess is the unit will have to be looked at by them.

As for it still running when you power off - it should still do that normally for 30 seconds as the internal backup battery has its own power/grounds or are you saying the D180 stays on longer than that ?

 

[Dynon]

A few things to look at. First, if you have an AP74 installed, you may have automatic screen dimming on. The auto-dimming is not absolute, though - you can change the offset using the BRITR and DARKR buttons. You might try disabling/re-enabling the autodim function as well. Does brightness react to the brighter/darker buttons when you disable autodiming? I think (I don't have a unit in front of me) there is also a numerical readout of the brightness sensor value on the autodim buttons that can help you determine whether or not there is some issue there. It may not react instantaneously to light changes - I think it has some delay by design. Finally, you might try doing a DSAB reconfiguration. That can clear up odd sync issues, especially after things have been removed/installed.

 

[jaba-who]

Hi Jake.
With regards the dark screen. The issue seems to be evolving.
Today when I turned it on in the dark hangar it was quite dark and gradually over about two minutes brightened up. Never took it out into the daylight at all.

WRT earthing through an alternate earth.
It runs constantly through an alternate earth. When I disconnect the main earth line it carries on as normal (doesn't give the red bar across the bottom and the label saying it's going onto internal battery. Just carries on regardless. However if I shut off the positive power it does go over to battery power and says it's running on internal battery.

I have rigged up a test lead (25 pin female din plug ) with only the power lines and if I disconnect all the other sensor plugs ( so remove all options for it to alternate earth) it acts as it should when I disconnect the earth line.

I'm going to run some exclusion trials with it today and see if I can work out which lead it's running the earth thfough. Might be all the earths or might be just one.

 

[jaba-who]

Hi Dynon Support

I've gone through the AP74 brightness controller and disabled it as well as enabled and changed the numbers. They can be changed from if I recall a low number right up to about 999 ( forget exactly what but somewhere about that. But doesn't make any difference to the brightness at all. Using the dim button sometimes makes it go black ( well very dark - just make out the info on the screen) and toggle it back to a darkened screen. So it works but seems to be like it's frame shifted to toggle between very dim and nearly black rather than bright and dim.

As I posted above it seems to be an evolving issue as today the screen opened up at very dark and gradually became bright over several minutes.

I'll do a complete reconfigure of the dsab and the AP servos etc and see if that helps.

 

[Dynon]

That brightness/darkness flip flop as you're dimming indicates that there's a problem with the backlight. We'll need to see your unit here for repair. Give our support team an email at 425-402-0433 or an email at support at dynonavionics dot com so we can help you further with this issue.

 

[jaba-who]

Hi DS
Thanks for that. It's been a few weeks since I have had a chance to do anything with the aircraft or the Dynon.
Ok on sending it back.
The issue I guess is that it's a 12 year old device and I am reluctant to go spending much on it if at the end of the day it remains a 12 year old device with the potential to have something else go wrong as well.

So I guess I'm going to ask you the impossible question - I apologise for the question but you just might have an answer.

Any idea of what a twelve year old D 180 is actually worth?
Any ideas on what the coats might be to fix this one?

If it's any help the current situation is:
Screen is now constantly very dim. Unreadable for about 5 minutes and then gradually lightens up to be readable with covering outside light or shading eyes etc.
still doing the dim and very dim flickering at about one second or so frequency.

Still obviously has an alternate earth and it seems to be doing it through either the 37 pin or the 25 pin male plug on the back.

The decision to replace with a new device or get it fixed is a difficult one and would be helped if someone with a crystal ball could give me some hints.

Thanks

 

[Dynon]

We have standard flat-rate pricing for out-of-warranty repairs (things that have failed, but not due to damage or abuse). For the D180 it's $250. See the out of warranty tab on http://www.dynonavionics.com/warranty-returns.php for the details.