It may sound silly; but, this is what I went through with the first couple of boxes my installer tried to fit me with -- hooked up to HDMI. Switched over to component and unplugged HDMI altogether -- went through the reboot/bootup cycle -- and it ran like a champ. Plugged HDMI back in and switched back to it at the TV. Fine as "can be". Went through the next few updates using component and switching back to HDMI like the 1st time. Though, the last update, went straight on through using HDMI. The component suggestion originally came from a Tier 2 tech support lady -- she said it works more often than not.