Red-X on GPS Control Panel

[flyboy62000]

I have two available MGL GPSs interfaced to the iEFIS system plus an external ARINC certified GPS. However, despite having good RAIM and signal lock, the red-X on the control panel and indicator in the iEFIS persist. I am running software version A1.1.2.2 Updating to 1.1.2.3 removed all MGL GPS data from the system and the red-x persisted. Rolling back to 1.1.2.2 restored GPS functionality, but the red-X is still present. All GPS feeds and positions are good. Not sure what's going on here, any ideas are appreciated.

[flyboy62000]

Still working to fix this GPS issues, but I have it isolated now. Here is the update, I'm about to rip out the iBox and send it back for repair...but that'll render my aircraft unflyable until it returns and require another pitot-static IFR check. So, I'd like to query the brain trust and see if there might be anything else that might be able to solve this GPS issue before I remove the iBox and send it off. It is winter, so it's not a bad time to do it if I need to, but I'd rather not. I spent a lot of money on this system, though and I'd like for it to actually work the way it's supposed to. I've been working on this system since June and still have not achieved 100% operability, but am down to just this one GPS issue. Everything else is now working well, but it's been a long road to get to the bottom of it. Perhaps this data will also be useful to the software development team. I'm sure Adam at Michigan Avionics is tired of answering my emails and phone calls about the same issue. If I can't resolve it by non-invasive means by Dec 18th, the iBox is going to Torrance to be opened up and inspected.

Symptoms:
1. iEFIS has persistent red-x on GPS status widget AND iBox GPS does not get a GPS signal.
2. iEFIS throws GPS Error Code 1 in system status box each time on startup.
3. iEFIS gets good GPS position via CAN bus from SP-12 and all iEFIS functions are normal on SP-12 signal. iEFIS displays SP-12 health data on both "internal" and "CAN" tabs on GPS status widget, which caused some confusion as it looked like both were good but was really only SP-12 data. iEFIS gets good signal and navigation from Garmin GPS via ARINC, but does not show satellite data bars on iEFIS GPS status widget.

Troubleshooting/Repair Steps:
1. Located and replaced bad MGL GPS antenna which was connected to iBox GPS, initially swapped with Xtreme and problems followed antenna, but no change to iBox GPS functionality. The bad antenna was causing a complete loss of GPS signal on Garmin GPS and Xtreme GPS, and reducing signal on SP-12 with subsequent loss of all GPS navigation in the entire system, replaced with new antenna and all external GPSs are now working correctly with good signal lock and feeding iEFIS properly.

2. Updated all iEFIS components to latest firmware. iEFIS firmware version 1.1.2.3. continues to cause issues with all GPS data coming into iEFIS whenever it is installed, rolling back to 1.1.2.2. returns functionality to all components except iBox GPS.

3. Rolled back firmware and tested each version from 1.1.0.3 through 1.1.2.3, determined 1.1.2.3 was causing problems with GPS functionality, but rolling back to 1.1.2.2 returned functionality, versions before 1.1.2.2 did not have any effect on GPS functionality.

4. Tested GPSs independently and together in various startup orders; this is how I found that the SP-12 status data was appearing on "internal" tab as well as "CAN" tab on GPS status widget. Only iBox GPS is not functioning properly.

5. I've eliminated static discharge, ignition, and other external noise sources as possible causes of problems with iBox GPS as best as possible, but do not have an oscilloscope to do further testing. However, other MGL GPSs on avionics bus are happy, so that leads me to figure the iBox is an outlier.

6. GPS antennas and units have proper ground planes and bonding to airframe static grounds.

So, I have a functional system that is degraded (inoperative iBox GPS) and displays a persistent red-x on the GPS status widget no matter which GPS feed is selected as primary (internal, CAN, or ARINC). iBox GPS is the only malfunctioning component. Is there anything I haven't tried that might address this issue, or should I just rip it out and send it back knowing I'll be grounded until it returns? Your input is greatly appreciated.

Adam Deem

[flyboy62000]

Problem resolved, bad iBox from factory. Returned for service and received new iBox, problem solved.