Facing TV Problems? Ask a TV Technician.
Hello, If it's shutting itself off before you can change the Input- then it's not due to it being on the wrong Input. This is caused either by a hardware fault in the TV (the Mainboard has failed), or there's a compromised HDMI cable installed in the set. Please unplug the TV from power, then remove any HDMI cables from the back of the set. Plug the set back in and turn it on. See if you can simply pull up the MENU (nothing needs to be connected to use the MENU), and navigate around- or if the TV shuts itself off again. Let me know what happens and we can proceed.
Is the TV staying on please?
Yes I'm typing. Okay the other Vizio is un-related to this problem. If Comcast working on the lines contributed to this set failing- it does not mean it would happen on every set in the house- just that it was likely the catalyst that caused this set to stop working. The cable is not the problem if the TV still suts off with nothing connected to it- this indicates it's internal to the TV itself.
If the TV shuts off right after the No Signal message then it's likely the Mainboard has failed.
Please try this. Disconnect the TV and the cable box from power, then press and hold the power button on the TV itself for 10 seconds and release.
Reconnect the HDMI cable making sure it's secure on both ends, then plug the cable box and TV back into power.
Turn the TV on and see if you can change the Inputs and find the one with the Comcast passport screen.
If not and it shuts right down then the Mainboard has failed and does indeed need to be replaced to fix the issue within the set. This is on average a $250 repair on this model unfortunately. If you'd like you can use the link below to locate a tech in your area:
Alternatively if you're a DIY type, the Mainboard can be purchased for $70 at the link below:
If you need further assistance let me know. Please do not forget to click the 5 STAR RATING, at the top of the page for my efforts. It is my livelihood and you can follow up at any time if needed.
Do you need further assistance with this?
I have no dealings with billing. I'm an independent tech. I provided the part and a link for you to replace it yourself and save $180 over what a shop would charge.