My Tivo 652160 reboots on its own maybe every 4-5 hours (maybe more, maybe less because I do not have the TV on all day). Everything will be fine and then it abruptly goes to a black screen for 1-2 seconds and then reboots going through the entire boot sequence. Once finished, I can watch TV until its next recycle. Occasionally (maybe once a week), the screen will be frozen when I first turn the TV on. The Tivo will be unresponsive to the remote control but it will reboot just fine if I unplug the power cord and then plug it back in. Upon reading posts here, I first replaced the hard drive and no change. Then I noticed that one of the caps had a domed top so I replaced it. No change. So next I have replaced all 9 caps located near the heat sinks. No change. I have run the Western Digital Diagnostics on the hard drive(s) in both Quick and Extended modes and both show no errors. Can someone offer some advice on what I should look for next? This is an HD model with a lifetime sub and I would like to save it.