I've purchased multiple DVR40s from eBay. A few of them are dead but the ones that will power up only have one functional tuner. The other tuner is pixilated. Is this a power supple problem, a hard drive problem or a main circuit board problem? I'm 99% sure it isn't my satellite because my other unit still gets signal. I also 99% sure it isn't my splitter because I have swapped the wires and the working one still works while the broken one still is pixilated. I recently had a unit die and pulled one out of my pile of used ones. To activate it, they made me get a new card. Unfortunately, it won't let me record anything because it wants to make a phone call. I plugged a line into the Tivo but it can't connect because no one answers (according to the unit). Is there a work around for the call? Is there a fix for the single tuner?