Hi - I'm sorry that this is going to be vague, but this doesn't appear to have a strong pattern, and I'm hoping from this basic description, someone's knows what's going on here...
System : Time Warner 8300HD cablebox/DVR - hdmi - Sherwood Netcastle R-872 (w/ Genesis Faroudja processor IC) - hdmi - Samsung 1080p LCD.
Above mention system was working fine - then Cable company replaced the DVR - I was hearing some hard drive noise.
Now - it appears that the Sherwood is having trouble with changes to the output formate from the cable box. When I change from standard def. to high def. the tv displays that it's search for a signal from AV unit - sometimes it just shows "snow". Turning cable box on/off usually helps. Problem also comes up when going from high def to low def. - and sometimes randomly between any channels.
Plugging cable box directly into TV, and everything works. It seems like the video process in the Sherwood is having a problem adapting with the incoming signals that the new cable box is giving it...