Ok, butchered a SCART cable tonight to disconnect the Composite Video In signal (plugged into my TV) and tested the cable on my various boxes.
- Thomson DHD4000 - unstable rolling output - i.e. RGB with no sync (expected as the sync is on the composite in)
- LiteOn 5004 - no video output - audio only (i.e. no RGB output)
Clearly the box has RGB-In through the AUX scart, and RGB-Out through the TV scart, since loop-through works (I can prove this by toggling the menus on my Thomson DHD4000 and the difference is visible) however it does not appear to output RGB through the scart.
Next I tried the separate RGB RCA connectors on the rear. These do output RGB on loop through, playback and tuner outputs. The top connector (Y - Green) has syncs, the Cb and Cr (Blue and Red) do not have syncs (this is expected). I used a composite-in from each of the R, G, B to prove this.
I can't easily prove whether it is recording using the RGB-In from the SCART as without the composite in as the sync might stop the unit doing anything with the RGB anyway.
This is a show-stopper for me. I will email them asking if there is a firmware release that can cure this, as I believe there was for the 5005. I'm a bit disappointed It's almost like they quoted RGB-In and RGB-Out as a feature when they're only a loop-through.