Fault finding on sat nav / screen

[Converse2020]

I have a retro fitted touch pop up screen display on my xc90 (old model) that plays input from separate DVD player, or sat nav or car camera (if I had one).

The whole setup has been in the car since 2010 and worked fine until recently when the sat nav display froze (screen went purple) and then refused to show sat nav output after a restart.The screen is motorised as on the factory volvo sat nav, and if it detects no signal on the selected input (DVD , Sat or Camera) will automatically lower. That's what its doing now - making me think the screen is not seeing an input from the Sat Nav, which is some unbranded universal WIN CE based Chinese device. I suspect this universal sat nav device has failed (though lights on the box still show etc) as i can still cycle through the screen inputs and watch a DVD from the glovebox DVD player for example.

The problem is that the sat nav device could be working just fine and it might be the input on the screen that has failed - but is that likely or a possibility?

What I would like to do is test the Sat NAV device to work out if this has failed, so that I might either fix it (unlikely) or search for a replacement? Any ideas how best to go about this ?


Thanks in advance

[Craikeybaby]

What is the output from the navi device? HDMI? Coax? LVDS?

[Converse2020]

Now you're asking - but I think its RGB ...

[Craikeybaby]

Could you try plugging into something else, like a TV? You would need a 12v power supply for the navi module.

[Converse2020]

The screen works - as I can watch DVDs on it so I am hoping its the sat nav device thats died rather than the input on the screen. Have bought another Nav device from China to connect to the screen to try and rule that out as seems the cheapest option.