I know there are tons of threads on this topic but I have replaced the power supply and the hard drive and am still having this issue. Wondering what else it could be... My TiVo Series 3 TCD652160 first started having issues after a power outage in our area. When the house power came back on my Tivo did not power back up. Nothing happened on the unit when plugged in (no lights, fan or hard drive spinning). Replaced the power supply and the unit powered on to the the Welcome Powering up screen. Next replaced the hard drive with a identical TCD652160 Western Digital hard drive. Same result, powers up to Welcome Powering Up and does not advance from there. Hard drive seems to be spinning. There is a solid green light on the front of the unit and lights near the ethernet port on the back. What else could be the problem? Is it a motherboard issue? Got all of my replacement parts from Ebay with sellers stating that the replacement parts are in working condition. Have called Tivo support 3 times. One lady told me to replace the hard drive and the other times they just wanted to refer me to Weaknees or to upgrade my Tivo stating it is a hardware failure. Have lifetime so trying to salvage this unit.