With no signal, or blackout function activated the image is no longer dark grey, but has slowly(?) become dark green. The blacklevel (greenlevel..) also seems to have raised. With 4:3 material I see this green tint on the side black bars as well. Probably also on the active image area, though not as easily noticed.

What is the likely cause of this?

Gunnar

Using the RGB color controls doesn`t affect the problem.