I just went through an issue with my XL4 that I'd like to share. I am a Cable One customer in the Prescott, AZ area. I got my XL4 in August 2012. Initially, my signal stregnth was on the Tivo channel stregnth meter was between 78 and 80 for all of my channels...SNR was 31-32. I had occasional issues with "pixelation" and I was advised by a Tivo rep to install an amplifier which imporved my sinal stregnth to 88-90...SNR was still 31-32. I had no further issues until last Friday February 15 when I lost 6 of my HD channels. Signal stregnth on the affected channels went from 66 to 0 while all the other operating channels were stable at 82 -85. SNR was 28-29. I bypassed the amplifier and went straight from the wall jack to the Tivo with a new cable and the signal stregnth was down to 74 on the operating channels, and absolutely nothing on the 6 channels I lost initially. I moved the Tivo to another room with a different cable input jack and the readings were the same. Cable guy came out Monday and immediately blamed the amplifier....I watched as he put his meter in the wall jack, and then in the amplifier output jack....the bar readings were obviously higher with the amplifier and he reconnected the cables using my amplifier in the loop. He changed the cable card with no improvement. He then got another tech out to the house and together they couldn't figure out what was causing the issue. They went outside to one of their trucks for over 35 minutes...I could see they were both on their phones. Finally one guy came back to the house with a splitter and proceeded to remove my amplifier from the setup....the other guy came in a couple of minutes later and told the tech to wait a few minutes before he hooked everything back up. He got another phone call and then told the guy that it was OK to proceed. Not only did the affected channels come in, but the signal stregnth was now at 92-94 WITHOUT the amplifier and the SNR was at 35-37. When I asked what caused this dramatic transformation the guy said "we removed your amplifier". When I questioned why this didn't cure the problem the first time he removed the amplifier he was mute.
There is no doubt in my mind that they did something outside of my home to the system to make this dramatic change. I am posting this so that it might be of some help when any of you guys/girls are dealing with a cable company signal issue. I wish they had shared what they did to cure the problem, but whatever it was, my Tivo has been operating perfectly since Monday evening.