DVR recordings are too dark to see properly

My dvr recordings are too dark to see. I get a signal sent to reset my box and that used to work, but now it only works for a few seconds and then the screen turns almost black again. I was advised to swap my box for  new one. Will I lose all my saved DVR recordings (that is: are the recordings saved in the box or in the "cloud"?). Also, does anyone else know why this happens?

Thanks!