FIXED-tech called before visiting house to trouble shoot.
Even though tv said "no signal", the tech had me use the mouse to access settings. I held the right button on mouse for approximately 10 seconds and heard the DVR beep. Right after that, the screen came on with all 4 cameras showing as usual. Checked the 2nd tv and it was fine also.
Tech stated that the resolution had been changed somehow and the tv didn't recognize the change. By using the mouse, it set the resolution back to default. He also stated that I might have to do this a couple of times to get the picture, but it will eventually remember the setting.
Save me a $65 service call.