Hello , my name is Jack Perhaps I can help you with this problem but first I must say that this vizio model was built largely with the same circuits as the LG 42PC3D and other models by samsung,HP,toshiba etc. except for the main board and this was a common problem for all of them.
Without being there with tools and meters ,I can still tell you that this is caused by the X/Z sustain board and be sure at 99.9 %
Not sure if you were looking into repairing this yourself but you can find this board at the link below;
You can also use the part number I gave you if you`d like to do your own shopping.
This board part # XXXXX cost around $70 to buy depending on where you get it.
In a repair shop you would be looking at a repair of approx. 175 to $200.
If you`d like to look into repairing this yourself ,I would help you along but a voltmeter may be necessary at some point.If you go for the repair shop option then click on the link below and enter your zip code ;www.tvrepairpros.com
This will give you a list of repair shops in your area.
Hope this help and I will be in standby if you have any questions.Thank you and please take the time to rate my answer if that answers your question and note that you can reach me here at anytime after this chat is closed if you have other questions.
Please note that there is just so much that i can do from where i`m sitting and if you are going to rate my answer below O.K service then i will get you a refund instead, just say the word.