The bottom segment on all digits is half-dim, though it improved as it worms up. The decimal point on the distance is missing.
I believe it is a KDI572 or KDI573.
A new one costs a few k! I belive it is just a simple box fed with RS232.
Sometimes this is due to a bad contact on the display. Just take it out and clean the contacts .
I have to agree with Michael, the first thing to do is to clean the contacts on the display. It works most of the time.
I hope you will let us know if it works @Peter
I have the same problem with the digit of my ADF screen (the classical Bendix) and I was proposed to change the screen for 500€ approx. which I refused.
Usually, only the lower digits are concerned (the bottom line) and things improve when it s getting warm.
Will try to get a photo.
Do we have to take all the unit out to disconnect the display ?
Yes I think so.
I will get this done at the Annual in January. Myself and my A&P/IA will be renting a hangar at a certain location in the UK because nothing can be done where I am based.
The display is multiplexed and the issue is either a bad connection to the display itself, or a duff driver chip. The chips are probably easily changed – unless they rubbed off the markings. I may have the MM in my collection and I have a contact who can get me any King MM.
a bad connection to the display itself,
This is a very well known issue with the Bendix/King gas discharge displays.
I think my DME has acquired an internet connection. I can see the logins into EuroGA, and here is the result
So what have you done Peter?