There have been a few random post throughout the flight sim community about this problem. There have been no serious suggestions how to resolve it.The visual problem is the avionics simply shutting down. They can be reactivated only by going to the aircraft menu and reselecting the plane. The fault may occur a few times in a 1 hour flight. I have a FS9 "pure" system. Only add-ons are FSNavigator and three DLL files for sound, squawkbox, and FSUIPC. My problem occurs flying the standard B737. The real cause is that the failure/avionics is set to cause a failure and CANNOT be edited to have no failure.I MAY have discovered the underlying cause of this. After searching the FS cfg files then the aircraft.cfg file and getting nowhere I decided to check these DLL. Over the last few days I've been looking for answers. I started with the HOSTSB.DLL file (in the FS9/Modules folder) renaming it and then logging onto VATSIM for a flight. All went well using the program SB HOST.EXE (which comes as part of the SquawkBox download). Later I tried another flight with HOSTSB.DLL reactivated - problem reappeared aqain.This evening I again used the SB HOST.EXE program and completed the flight without incident. So assuming that 1 + 1 = 2 I may have found the cause of this problem.bfPS who is the author of HOSTSB.DLL anyway?

Today the bad news!Flying VATSIM this afternoon and applying my own theory I was extremely disappointed to see the avionics display shut down early into my flight.In a short flight of around 250 nm the avionics failed at least twice.Back to the drawing board.QuestionWhy are there no replies to this series of posts? Is this fault uncommon? It would certainly appear so given the difficulty in obtaining eith information or assistance.bf

As to your question about no replies: I have never experienced the problem with failed avionics and I do fly quite a lot. That may be the same for many others. And that could explain the "no-replies".Jozef http://www.dse.nl/~joker32/pictures/signature.jpg

JozefHow great to hear from you. Like a man in solitary any voice is welcome.Suspecting, or knowing, that your comment was indeed the most likely explanation today I made a different test.This time I flew the default 777 (instead of the 737) and completed a 1 1/2 hour flight without incident. Perhaps the problem I, and a few others, have noticed only appears under a very limited set of circumstances. If so I can live with that.Again, great to hear from youbf

Thinking about your avionics problem, could it be a battery draining problem? In FSUIPC there is an option to cure that.Otherwise look at this message:http://www.fsgateway.com/tips_read.asp?id=5Jozef http://www.dse.nl/~joker32/pictures/signature.jpg

JozefThanks again for your info. Actually the good suggestion at FSGATEWAY was tried by me. I came across the same information while looking over my aircraft.cfg and I thought for a short time that had worked but unfortunately not.Note that it is not at startup but long into a flight that this problem occurs. Also, it is clear that the problem is to do with the Failure Settings. Somehow the avionics setting gets set to failure while in flight. When that happens nothing short of reloading the airplane will reset it. It's not so much a battery drain as it is a "programmed failure" when no failures were activated by the user. It is extremely strange, not only that the setting changes in flight, but that it cannot be reset by usual means once it does kick in.I have the habit now of checking the setting prior to takeoff and all failures are OFF. When the shut down happens a recheck shows the same failure with a red check mark.Bizarrebf