Just picked up a quad HDMI box, using an older (2016) Vizio TV. CEC is enabled, and the Tablo is seen in the registered devices.
Tablo is connected via HDMI to a non-ARC HDMI port of the Vizio. CEC is enabled on the Tablo, both wake and TV off.
TV off works just fine, but when wake is enabled, the TV will turn on every 20 seconds or so, very consistently. I turn the TV off again, and the Tablo wakes it up again without any input on my end, even if the remote is in another room. If I turn the wake option off, all is well. But I’d like to not have to reach for my TV’s remote to use the Tablo.
I have a Vizio that did this as well, just not as often as you. I think this is a fairly common issue with Vizios. IMHO, Vizio has a great picture for the money, but the interface is clunky and I have to reboot it too often as it gets really slow in responding to inputs at times.
Anyway, I found that if I disabled the TV’s wifi, it quit turning itself on. With the lousy ‘smart’ TV interface on Vizios, it’s not a loss (at least for me). I’m using a Roku to stream Tablo to it.
I have a 10+ year old Vizio TV (with CEC turned on) that has turned on in the middle of the night several times over the last few years. We always figured it was the Roku Ultra remote doing it. That remote has always been flaky doing weird things all the time. It wouldn’t have been the TV’s remote as it is always in a drawer not able to aim at the TV. My Tablo is a 7.5 year old original 2 tuner.
The Vizio TVs I had that were connected to the internet would come on randomly and the light would slowly blink sometimes. If I recall correctly this indicated they were receiving a firmware or software update.
I also have an old Vizio with a flaky CEC. The volume up/down buttons will only work if you haven’t done anything else with the remote for about 30 seconds. During the 30 seconds while the Roku remote cannot control the volume via CEC the native Vizio remote can change the volume.
The powering on issue isn’t just an issue with Vizio TVs. I saw the same behavior on my panasonic VT55 and on both of my new Sony oleds. I now just leave CEC disabled on the tablo…