Originally Posted by Will Munshower
I'm assuming (since you said the cable goes from the box to the TV) that you do not use an AVR. That being said, the loss of video sounds like an HDMI handshaking issue. As far as the 'pops', I have that happen as well. Especially when I'm watching Hulu or any other IPTV provider, for that matter. What happens is that right before any program begins, I get kind of a 'thump' sound from my speakers. It's actually reassuring since when I hear that sound, I know I'm actually going to have my selection streamed to me.
I recently installed my 52v5100 and use it primarily as a computer monitor for gaming and movies, but also as a sleep timer, in SD tv mode, off of a cable box.
I never get the "pop" while swapping channels in SD from cable, or while watching videos from my computer, but if I alt-tab from some full screen games, which causes a temporary loss of signal, I absolutely get the "pop". This happens if muted or not. I do not run any audio out of the TV while it's used as a monitor, so I cannot comment on the "pop" traveling through the audio circuitry (though I could test it if someone would like). The Sony, my computer, and everything else, is run through a commercial quality line conditioner (not a surge strip), so voltage fluctuations should be modest at the AC point. I'm using a DVI-to-HDMI connection. It's really not that big of an issue for me, as I believe it's intended (though quieter would be better).
Even my cable box, not connected to anything but an AC source, makes a somewhat similar pop if you turn it on or off (although quieter). Normal electrical discharges, I would assume.
High end amplifiers, and pre-amps, for years, have often had "soft-on" features. This is designed to power on the amplifier section later than ASAP, in order to reduce, or eliminate, the powering of the capacitors to carry into the output section audibly. It's only an aesthetic difference in an amplifier, unless the thump is so extreme it could damage the speakers, so it's unlikely that you need worry.
My guess is that it would be related to the backlight and capacitors dumping their stored energy and then re-starting, and nothing abnormal.
I'm curious if anyone feels that it could be detrimental to the set.
I noticed Sony implemented an option to swap to standby when no signal is present (apparently in case you turn off your dvd, pc, etc.., it will standby like a monitor and mostly power down). I found no reduction in the pop effect with this mode engaged. I also "pop" if I turn off the computer while the Sony is still set to the HDMI output from the computer.
/Sorry for the wall of text. My eyes are buggy today, because of conjunctivitis, so I don't want to spend much time making a prettier post.