Apple TV: "No signal" when I switch inputs?

This is one of the trade off's with HDMI, in basic terms it is unlike other connections in that it is intelligent, if it doesn't detect a flag that tells it your device can't copy the source it will turn itself off.

How long have you tried waiting for the tv to show up on your screen? Have you tried pressing a key on the remote instead of restarting the tv?

HDMI can have some sync delays, and I've sometimes had it take up to 30 seconds before anything appears when switching inputs. Further, sometimes the initial screen that appears is the screensaver, depending upon what state you left the tv in before.... In this case, photos or album covers do eventually start scrolling up the screen.

If all else fails, you could also try using the component outputs on the tv. It's messier as it requires four or five cables instead of one, but the quality should be equivalent unless you have a TV that does special processing via HDMI, and it will eliminate the delays in switching inputs.

If all else fails, you could also try using the component outputs on the tv. It's messier as it requires four or five cables instead of one, but the quality should be equivalent.

I'm not too sure I agree with that.

I'm not too sure I agree with that.

With which point? The quality being equivalent?

It largely depends upon the TV you're using, as some of the lower-end HDTVs have skimped on their component input designs in favour of HDMI. Further, some of the higher-end TVs that will do 1080i->1080p de-interlacing will only do this on the HDMI inputs, and not the component ones.

Note that this may not be true for all source devices either (many HD-DVD and Blu-Ray DVD players provide poor quality component output as well), but as far as the tv is concerned, the output quality seems to be pretty on-par using either method. This is based on a bunch of testing that I and several others have done, using several different TVs.

There is no visible distinction on my 32" HP LCD TV (720p) using HDMI vs component from the tv. I simply use HDMI because it requires one cable instead of five.

On my Toshiba 62" DLP TV (1080p upconversion), using the component cables makes a noticeable difference with photos and higher-end HD content, but obviously is indistinguishable for source content that's only 640x480 or less to begin with (which is 95% of my content right now). With the Toshiba, I blame the issue on the component inputs not doing the 1080i->1080p deinterlacing conversion that occurs on the HDMI inputs.

Note as well that you do have to use good quality component cables that are properly shielded, since the temptation is to cop out and use normal RCA audio/video cables. These will make a difference if the cables aren't up to par.