I have a stock Series 3 (I'll call it U1) I that will not boot up. When powered up it never gets past all lights on the display on for 60-70 seconds then all lights off for 10 seconds then back on for 60-70 seconds. I have both HDMI and s-Video outputs hooked to TV's. The s-video and the HDMI has no picture but the TV indicates it see a HDMI signal while the TiVo is powered up. This started after a lightning storm and power outage it however is on a UPS that will last 10 min or so. I have another Series 3 that is in good working order (I'll call it U2) that I have used for trouble shooting. I have tried the power supply and HDD from the broken U1 in the good U2, U2 works fine with U1 parts. I have also tried the broken U2 HDD and power supply in the good U1 and I'm experiencing the same problems. Essentially I have proven everything but the main board is working. Is this how a TiVo typically acts when it has a main board failure? thanks in advance for any advice that you all may have.