Dynon D100 Display Slow To Warm Up?

[CTSW Bob]

Hello- in my 2007 CTSW, my primary flight display Dynon D100 on my left side does not like to come on when cold.  The right side engine monitor comes on within seconds when cold.  I’m talking about 40 degree weather and below.  The left side PFD will not come on for sometimes over 10 minutes or longer.  When it finally comes on, it is black and white for the first few seconds, then the color comes in, dim, and then within 60 seconds all is good and normal.  
 

Any ideas?

 

Not sure if I want to drop in a new HDX display, as I believe you are supposed to do both displays at once.  I could see it topping $9-$10k pretty fast.  Obviously won’t be a problem when the weather warms up, but I’m thinking it is sending me warning flares..

 

Bob

[cdarza]

Ive had that happen to my D100 -   at first just a few seconds delay and overtime it was just like yours - 10-30minutes until eventually it wouldnt come on at all.   I sent my mine in to Dynon who repaired it but the same thing happened again many months later - sent it in again and thus far been ok.  I didnt get any detailed service report as to what exactly had failed or what the scope of repair was.  Unit is quite old so im looking to upgrade when it fails next. 

[CTSW Bob]

Thanks for the reply.  I’ll call Dynon today and see what is involved with an upgrade or repair.  At over 13 years old I’d imagine there’s been some substantial advances in technology.  

[Ed Cesnalis]

12 hours ago, cdarza said:

Ive had that happen to my D100 -   at first just a few seconds delay and overtime it was just like yours - 10-30minutes until eventually it wouldnt come on at all.   I sent my mine in to Dynon who repaired it but the same thing happened again many months later - sent it in again and thus far been ok.  I didnt get any detailed service report as to what exactly had failed or what the scope of repair was.  Unit is quite old so im looking to upgrade when it fails next. 

 

2 hours ago, CTSW Bob said:

Thanks for the reply.  I’ll call Dynon today and see what is involved with an upgrade or repair.  At over 13 years old I’d imagine there’s been some substantial advances in technology.  

I just upgraded mine. $350 is the base fee no matter what is wrong.  $150 fee for using an existing rebuild instead of getting your old one back.  $150 was another charge I paid for a backup battery.  All in all good value and good support.

[CTSW Bob]

I was quoted $450, just as their website, and roughly a 10 day turn around from when it is received.  I put in for the return authorization and will report back.  While I would love the latest and greatest in my plane, and would upgrade if I only had to do one screen, I can’t justify dropping the funds for two screens when I only fly VFR and my Garmin Aera 660 drives my auto pilot and ForeFlight does the traffic and weather.  $450 is easier to swallow and Dynon should be commended for standing behind their older avionics and repairing them for a reasonable fee.  

[CTSW Bob]

Here’s an update:

It took a month (2 weeks of that was shipping there and back), but I got my display back.  It was 70 degrees yesterday when I installed it and went flying, so I don’t know if the cold weather problem was solved, but Dynon did acknowledge a hardware issue and replaced whatever they replaced.  
 

Here are some tips I learned after the fact:

1.  They updated the software, which is fine, but now it won’t talk to my Dynon D120 engine monitor.  They can both be run independently, but I can’t transfer the engine data to my PFD or flight info to the right side.  I have to update the software on my D120 now.  In order to do this, you need a Windows based computer, a RS232 to USB adapter, and back up power for your plane and make sure you have 120 volts for the laptop too as it can take a lot of power and time and you should not rely on the batteries.  If one shuts down during the upgrade it can lock down your displays requiring them to be sent back to Dynon to be repaired.  

The good:  The software update is free.

The Better: Dynon would have updated my D120 for FREE if I had sent it in at the same time as my D100.  Had I known this, I would have chosen this route 100%.  
 

Now I am awaiting a new power cord for my wife’s old laptop and an RS232 to USB cable from eBay.

 

2.  Looking at the software update notes, there are several updates that pertain to the erratic oil temp readings that I and others on here are experiencing.  Sounds like the demon I have been chasing since I’ve owned this plane is a software issue.  Go figure.

 

I will report back when I get this all done.

Bob

[Roger Lee]

Both Dynon's must have the same software to operate correctly. Same for the Dynon autopilot if you have one. Updates are free, but I doubt you'll ever see another one for the D100 and D120

[CTSW Bob]

So this week I decided to update my engine monitor (Dynon D120).  I hooked up a battery charger capable of up to 15 amps to my plane and ran the old laptop off the power cord.  The update took roughly 45 minutes and if anything were to shut down during the process the screen would have to be sent back to Dynon for the fix.  I figure that would cost me another month with the shipping times.

 

I had a few glitches getting the software to download onto the laptop until I gave up, downloaded it from my home computer onto a flash drive, and then from the flash drive to the laptop.  Should have done that move first.  Second, I did not get the right driver downloaded for the USB to 9 pin male adapter.  Once I figured that out it was smooth, but nerve-racking sailing.

 

On our CT's (at least mine), I could leave all the "avionics" off by only turning on the breaker for power.  You only want the part you are upgrading to be on, which for me, was my D120 engine monitor.  I pulled out the Dynon to unplug and access the 9 pin connector at the harness.  During the software upgrade, wear good walking shoes as I was pacing like an expectant father in a waiting room.  I did NOT want my plane to be down another month.  I think I walked at least 2 miles around the airport as I would have lost my mind in anticipation staring at the computer screen.  

Once all was done, simply power down, unplug the cable, plug back in the factory connection, and button up the dash.  I was happy to see all the information from my PFD and my EMS share back and forth.  Phew!

 

 

[CTSW Bob]

P.S.  Upgrade did NOT fix my erroneous oil temp readings. They are all over the place with wild 100 degree swings or better every second.  I have replaced the sensor, replaced the connector, replaced the wire going to the harness, and even played with the sensor type in the setup menu on my D120.  I thought I had it solved when all the software updates included corrections for "fluctuating oil temperature readings."  No luck

 

[GlennM]

Run a 14AWG ground wire from the stud at the back of the Dynon case to the aircraft ground "comb".  You will need a small ring connector, 8-32 nut, and insulated female spade connector.  

 

Mine jumped for almost 14 years until I fixed it last month.   The Dynon installation manual mentions case grounding when panel is not grounded to the aircraft ground, like in our composite planes.  I was surprised not to find one,  but by adding it, all my temp fluctuations went away.

[CTSW Bob]

Interesting.  Could it be that simple?  Everything else runs smooth, just the oil temp.  I will give it a shot as I have nothing to loose but a half hour of my time and everything to gain!

 

 

[GlennM]

It was that simple for me. I was at the end of my rope with alarms and was planning to take it to the avionics shop in Lakeland  (KLAL) and have them deal with it.  As my one last attempt to figure it out before doing that, I decided to look up the installation instructions.

There is a whole section near the front about grounding and tying in with the aircraft ground.   On a metal aircraft, the ground is pretty much the whole structure of the aircraft.  Not so with composites, I realized.  There are ground leads from the sensor cables that come with Dynon,  those were attached to the ground "comb" for the spade connectors already.  Not being an electrical engineer, I can only assume, the case ground must float and since the oil temperature sensor is grounded to the engine, the difference between the case ground float and the aircraft ground causes the errors and jumping. I had issues with the CHT jumping at the same time and these were resolved with the case grounding, also.  

I think I was headed down the wrong trail for a long while because I was thinking the oil and CHT were from spurious voltage spikes from the charging system. So, I put in the big capacitor and that did not change anything. 

 One day, my hangar neighbor mentioned the Rotax oil and CHT probes were thermistors,  which meant as the temperature rises, the voltage output of the sensor decreases, unlike a thermocouple, which is opposite.  In my understanding, the bad ground was reducing the voltage seen by the Dynon, resulting in a higher temperature reading.  This could all be a wrong interpretation,  but it ultimately lead me to check for the case ground,  which solved the problem.

I still have issues with  the EGTs reading low and jumping, which were not affected by the ground wire addition, but those might be related to loose pins in the connector at the back of the Dynon.

 

Please let us know what happens!

[CTSW Bob]

I will.  I hope to play with it this weekend.

 

Thanks for the tip and education.  
 

[GlennM]

 

On 3/17/2021 at 9:31 PM, CTSW Bob said:

I will.  I hope to play with it this weekend.

 

Thanks for the tip and education.  
 

Did you try it?

[CTSW Bob]

Hi Glenn - Thanks for the inquiry.  I did, but no joy.  Still swinging around in flight.  Stable on the ground.  Still getting the best of me.

 

 

 

[GlennM]

I am sorry it did not work.