Aircraft avionics - cockpit LCD display / MFD reverse engineering

[adriansmith31]

I have acquired a MFD from a RAF Nimrod MRA4 which is a LCD unit 9" square with believed resolution of 768x768. It runs off 28V DC and I have successfully managed to power this thing on but at startup it displays a large "T" and then after a period of time displays a green diagonal line which in avionics speak means no input signal or data.

I've done a video of the power up sequence and teardown but I'm wondering if there's any avionics engineers that are familiar with similar units or could give any sort of idea what video input this needs. There are three coax connectors on the back which eventually go to the video processing board where they are fed into a triple channel video amplifier and then into a ADC. It looks like the unit takes 3 video inputs (9 coax connectors in total) but only three are fitted.

There's an absence of MILSTD and ARINC transceivers which after doing the teardown I believe this is purely an analog display and it doesn't generate any symbology within the unit itself like the MFD's used in commercial aircraft. It's been suggested I try component video or 768x768 @ 50Hz sync on green but I don't have any way to generate this signal.

Video of it powering up is here if anyone is interested https://youtu.be/ugQ7-Vc6U1g