AF-5600 Intermittent boot-up issue

Having a problem where the EFIS frequently does not boot up correctly. This occurs even with no USB and no SD card inserted. It also occurs whether the unit is started with the Master switch or by holding Button 1 on the EFIS (the EFIS does have a backup battery wired). When turning on the EFIS, one of three things happens:

1) The system boots up normally (less than 50% of the time)
2) The AFS logo appears, the screen flashes briefly (I believe this is the GRUB boot loader screen), then the AFS logo returns. No progress is made after this, the unit seems to be hung.
3) The fan comes on, but the screen stays dark.

What is the best way to debug boot-up issues? We have already run through the BIOS settings changes as recommended by AFS. For #2, would it be possible to see kernel boot-up messages instead of the AFS logo? I have no idea where to start for #3...

System logs can show some valuable data in these issues.With an SD card installed press the following sequence: SET -> LOGS -> SYSTEM

Email us info@advanced-flight-systems.com attaching the *.ALS file from the SD card.

Thanks, I'll get that info to you.

Relatedly, is it possible to disable the splash screen, so that the Linux kernel console output can be seen during boot-up? I can attach a USB keyboard as necessary.

No, this isn't a feature of the AF-5000.

After blanking and reformatting our terrain USB drive, we have not seen any more occurrences of the splash screen hang (#2 above).

We are still seeing occurrences of the "black screen of death" (#3), however. I noticed one potentially interesting symptom. On a good boot, I hear the fan spin up normally. On boots that fail, the fan starts to spin up, but then stops again after less than a second. Then, about a second later, the fan spins up normally. I only hear the fan "hiccup" like this when the EFIS fails to POST.

Does that information provide any insight to possible causes? Additionally, I did forward the logs you requested, however I suspect they won't be very useful for the "No POST" failure.

Thanks in advance!