I have a Comcast Motorola DCH3200 used to send signal to my LCD tv. My LCD tv worked fine before I had to get the DCH3200 for the DTV switch over. Now, after about 90 minutes, the picture goes black and my tv has the the message, "no video".

I am guessing that the DCH3200 is overheating, because after turning it off for about 10 minutes, the picture is back and goes black after about 45 minutes the next time.

The DCH3200 is sitting with clearance in a relatively cool part of the house but is definitely the warmest piece of my equipment when touched.

Any ideas? Maybe a defective DCH3200?

What resolution are you using over what interface to your LCD TV?
Does the sound also stop when the video does?
Does the 3200 unit have clearance under it it as well as around it?
What make/model LCD TV do you have? If only a couple of years old it should have an OTA digial tuner.
If you use a splitter and also connect your cable directly to your TV can you get the analog channels from your cable company without trouble.