Epson EH-TW6700 since today shows only light blue image

[pikim]

Hello,
I have an Epson EH-TW6700 projector which worked like a charm until yesterday in the evening. When I started it today it showed the desired image in very strange colors. I turned it off an on again and since then it only shows a light blue image. Depending on the content it should show, it sometimes gets a bit lighter and darker, but the whole screen has the same color. It also doesn't show the menu. Changing the HDMI input also doesn't help.

Anyone ever heard of such a behavior? Any ideas?