I will describe here how to restore a "bricked" iEFIS G3. It is quite simple.
First a bit of background. The G3 uses a Texas instruments processor. This has a built in boot system hard coded by Ti. The first thing it does is look for a file called MLO on a disk. This disk is a Micro-SD card inside your EFIS. If it finds the file it loads it and passes execution to it. MLO is the first bit of "MGL" code that executes and results in a bit of writing on the top left screen.
So if you see that writing - the internal disk is OK and MLO is there. MLO does a few housekeeping things and then looks for the file EXP3.BIN (that is the file you download from our website as update - it contains everything, the operating system, the EFIS application and the default screens). This is expected to be on the internal disk in the root folder (so you would have two files there at minimum to start - MLO and EXP3.BIN.
If EXP3.BIN exists - it gets loaded and you should be fine.
If you only get a black screen (no writing on the top left) - for some reason MLO is not there or the internal SD card has failed (that's rare).
Lucky - the iEFIS can also boot from the external SD card slot and that is the easiest path to get things going. There is one little issue though. Ti in their wisdom insisted that the SD card must have a partition table and the usual disk formatting tools do not do that.
But there are some that do. Most of them require a degree in physics to operate. But there is an easy one on our website. It is RUFUS version 3.8. Rufus is a very nice and easy to use tool written by the Linux community (it runs in Windows so no issue). Here is a link: www.mglavionics.co.za/Firmware/rufus-3.8.exe
It's small and powerful.
Use this to create a SD-Micro card you can boot in the EFIS. When you run the tool please select that you want create a "FREEDOS" bootable disk. It will create a disk with a Microsoft DOS clone (we will not use any of that but it happens to create a partition table).
Note: In Windows 10 you may have to right-click on the rufus file and select "run as administrator".
Now all you need is MLO. Get it here: www.mglavionics.co.za/Firmware/MLO
Copy MLO to your newly formatted FreeDOS SD card (root folder, there will be a few other files there now - just leave them).
Now insert into your EFIS and switch on. It may take a few seconds and then some writing should appear. If the internal disk has failed it will tell you that it has a serious problem and cannot start the internal SSD. In that case the internal card need to be replaced. It is located in a little flip holder. Sometimes it just needs to be taken out and put back (perhaps a bit of corrosion on the contacts) and things work again.
Anyway let's assume all is well and the internal card starts. If just MLO is missing but the internal EXP3.BIN is there - it will be loaded and the system is up and running again - in that case just use the internal file manager to copy the MLO from your external SD card to the internal card and you should be back in business.
If for some reason the internal disk does not have the EXP3.BIN - simply copy it to your SD card (the one you made) and start up again. MLO will copy it to the internal disk and start it without you needing to do anything.
You can also do another trick: You can actually run an external system from your self made SD card. Just rename your EXP3.BIN to EXP3.EXB (for eXternal boot). In this case MLO will load your external EXP3 copy without doing anything to your internal disk.
Now, regardless of how you get your system running again. Please, once everything is in place - make a BACKUP. Your system has a really nice backup function that creates a sector by sector exact identical copy of your internal disk to an external SD card. That means you have a complete clone. There is a document on our website that explains all the things you can do with that.
Direct link: http://www.mglavionics.co.za/Docs/G3%20cloning.pdf
Sorry for the technical post but I hope this information can be useful to other G3 users as well.
CEO MGL Avionics