I have 2 lifetime Series 3 TIVOS. One works great but the other has started spontaneously restarting itself; sometimes 3 or 4 times a day. I suppose I could try replacing the power supply or hard drive (or both) but I'm not confident that will fix the problem. I'm satisfied with the capabilities of the Series 3 so I'm looking for a replacement with lifetime service. Ebay seems to be a crapshoot; I'm finding nothing on Craigslist. Can someone suggest a source?