I have 3 EFIS Screens, 2 5600 and 1 5500 installed with a VPX-Pro. My middle screen is 5500 and has the engine monitor board and where the VPX info is connected through. This last week I was up for a flight and noticed while viewing the VPX Electrical screen, the circuits would go away and then immediately re-populate. Over about a 45 minute flight, it happened 4 times. Returning to the hangar I pulled the efis and checked the wiring between the 5500 and the VPX and could not find any loose connections.

Then last week on the way to Airventure I had that electrical screen up again and once again it was doing the same thing. Then to add to this, every so often I would get a warning "check oil pressure" or check fuel pressure", etc. and then they warning would immediately go away. Everything looked normal and seemed to be just a wiring issue so continued. Now it seemed to be more of a communication wire though the Ethernet so checked all the connections to and from and they all seemed to be working fine.

When returning home from Airventure, it continued to happen only more often and for longer times. Once the engine info was out for about 3 seconds. Once back on the ground pulled all the EFIS systems from the panel and left connected. Turned everything on to see if I could find a loose wire or something else. I continued to happen while testing, but never when I was fiddling with the wiring. After pulling every wire to check, and re-connecting everything, it still did the same thing.

From what I can tell, this must be something with the 5500 screen and the communications it is sending to the other screens. Could this possibly be something within the EFIS itself since it has to do with both the engine monitor and the vpx?

Any help to further investigate the issue is greatly appreciated.

Thanks
Brian