AP74 & D180

[DMACLEMENT]

Good afternoon

I am experiencing difficulties using the AP74 value knob and discussed this with Jeff Fox at DYNON while the Forum was down.

I thought I found a solution to the problem but it surfaced again a couple of days ago during a long flight.

Here is a summary of the difficulty. Normally with the engine running, D180 and AP switched on, turning the value knob would open the HDG window, a push would activate the ALT window and a second push the BARO window. Unfortunately, this knob now seems to be inactive. It is only when I insist (more then 10 times) that I can get the knob active and most of the time without success at all.

A couple of months ago, I decided that I should use AIR DUSTER and CONTACT sprays, having removed the knob. And that did the job... for a few weeks !

Jeff was happy with this result although his original thoughts concerned the cabling and connector. And he might be right.

Any history of such problems withe the AP74 ?

Dominique

 

[Dynon]

No, I don't believe that is a common or "known" problem.

 

[DMACLEMENT]

Thank you for your reply.
Food for thought...
In flight, while struggling with the AP74 which would not answer to the various pushes, I finally ended up with trying to adjust the baro data thru the use of the D180 buttons. This could not be done because my engine was overheating sending alarms to the D180 screen during which events no action was possible on the D180 AP buttons. After acknowledging the alarm to erase it, it came back immediately.
My questions is : whilst I understand that alarm bars displayed on the screen prevent any further action through the buttons (with the exception of the ACK button), could it be possible that such alarms prevent any action on the AP74 as well ?
Thanks for your help.
Dominique

 

[Dynon]

I don't have a way to simulate that here easily, but that actually could be the culprit.