Red X on TV for the 3rd time in 2 months

I have 3 receivers total in the house and the other 2 work fine! The one not working in the DVR. The last two times the X appeared I disconnected to power cord for 10 secs and that worked! This time it did not so I tried the holding down the down arrow and ok button option and it never didn’t anything but flick to a screen that said no signal then back to the red X! I tried this 3 times holding the buttons longer each time! I’m honestly sick of this happening. I’m sure it’s not the wiring in my house because EVERYTHING else still works and no receivers have been moved! HELP!