I had the same problem and upon inspecting the board I discovered R15 on the board was totally corroded and as soon I tried cleaning it, it came right off the board. I was able to remove it, clean it and solder it back on. Problem was solved immediately. So inspeat your board and if you have soldering skills you can repair it yourself.
My Vizio E601i-A3 suffered the exact same problem "Loud noise, then TV shuts down" but replacing the power board did not fixed it. Replacing the Main Board solved my problem. I found this note after on shopjimmy.com which actually discussed my symptoms. http://www.shopjimmy.com/vizio/e601i-a3 Vizio Y8385864S (01-60CAP001-00) Main Board (SEE NOTE!) This part is compatible with all versions of E601i-A3 and E601i-A3E This board may or may not have connectors at location CN13 and CN24. 01-60CAP001-00 and 864 is found on sticker. IMPORTANT: If your TV has No Picture/No Video, this is likely caused by a bad T-con board, and NOT a bad main board. Symptoms commonly caused by a bad main board in this model include -No sound -Loud noise, then TV shuts down -HDMI inputs non-functional -TV will not tune channels -No internet connection -Internet apps open and TV locks up