Whilst I was on covid lockdown I bought several avionics parts with the intention of making teardown videos and seeing if I could possibly power them up. If you are a frequent visitor to this site and / or my YouTube channel then you will already know this but for new visitors please check my other posts and my YouTube channel for more avionics teardowns.
I have a cockpit LCD display unit from an RAF Nimrod MRA4 which was a cancelled project to upgrade the existing MR2 aircraft which included new avionics and several aircraft were built but later scrapped before they entered service due to the project’s cancellation. Somehow many of the parts ended up on eBay and I’ve found by doing a little research these display units have found their way to home cockpit flight sim enthusiasts wanting to see if they can be used. Short answer to that question is possibly but from my teardown its likely they need a specialised video format and / or additional signalling to select inputs. My unit seems to be possibly faulty / broken as well but I will find that out once I get a power supply that can handle it as it draws over 5 amps at 28V. It’s explained in the YouTube video but for now here are some photos of the main boards.
I will try and power the device up at a later date and try and find out what video signals it works with if possible. Of course, I will report any findings here and also do a video if required.
YouTube video
Photos of the main circuit boards
Well I managed to get this powered up and display a start up / no signal symbol. Next thing is figuring out what video input it needs.
I’ve posted a couple more videos on my channel.
Hi! I did my own research and some reverse engineering. I was buying some of this units for flight simulator use. I thought they might be similar to Airbus DU but unfortunately they are not. I was able to power up one unit too. So far it displays only the letters L,T or F. By counting the pixels I was calculating that the resolution is only about 512×512, not 768×768 like the Airbus DUs. I am pretty sure that they are not simple analog monitors. Similar to the Airbus DUs they receive digital data from the aircraft systems and have their own symbol generation/ graphics generator to display them. Probably they contain all software for all possible modes/positions like PFD/ND/ECAM. I think they have the additional analog video input only to display signals from a external camera or similar for military purposes. Probably after reset they expect at least a switching signal on some pins to activate the analog input. I haven’t been able to figure out so far how this works. I also not sure that the digital interface is based on Arinc429 like with the Airbus DUs. Maybe they use a military standard instead. The diagonal line that is shown on your unit is not shown on my DU. For Airbus DUs this line means that the unit is defective.
That’s good info, thanks. As for the digital inputs I’ve been able to determine it doesn’t use any arinc or mil-std1553 input due to the lack of any transceiver chips or modules. There are 4 RS485 / RS422 inputs brought out onto the rear plug and a fifth goes to header on the main pcb presumably for repair workshop or factory use. The other pins appear to be for switching or control inputs perhaps by grounding them to enable a particular input or mode. But its very difficult to reverse engineer due to the design.
The only recognisable input is the three coax inputs go to a triple channel analog video amplifier chip which is then connected to an analog to digital converter which in turn is connected to one of the asic chips.
The line must mean my unit could be faulty in that it fails its power on self test.
Sorry for the late reply, the system doesn’t seem to be sending notifications.