I've got my television hooked up to the component monitor output or the 990 and all component inputs are switched without problem.
I've tried two devices (and multiple cables) but can't seem to get devices using S-video inputs (video 3 and video 4, if that matters) to display on the monitor using the component output.

I've read and re-read the manual and it seems to clearly state that "Any signal that appears at the S-Video input jacks) is automatically send to ...the componwent MONITOR OUT jacks" - page 20 among other places.

The configuration seems to be okay in the 990 menu (specifying S-video as the video input). Is there a trick to making this work? Am I just crazy?
Thanks.

Only one thing occurs to me right off the bat. Does your display's component input support 480i signals? In some cases, TV's will have one component input that only does 480p or higher resolutions and one that'll do 480i - in which case, connecting the component monitor out to the 480p+ input on the TV would yield no video for transcoded s-video (which is 480i).

According to the manual (it's a Toshiba 65HX93), it will take 480i on the component video inputs. I appreciate the idea, though.
In the interim, I'll run an s-video cable to the TV as well and switch inputs when necessary - not optimal, but it should do the job.
Thanks, and I'd be more than happy if any other ideas come up.

I'm having a similar issue with my 1070. No interlaced signals are passing through the component out, at least that my Sony CRT can detect. Same component input works fine with direct interlaced signals.

The seemingly bizarre thing is that on mine component 480i is coming across the S-Video out. Are all your switched component sources progressive?

The component sources are a mixed bag. Some are progressive and some are not. All of them come through without a problem over the component output.