Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

[Kharn]

I have a ~4 year old Vizio VT470M that has worked flawlessly until this morning. Now when I turn the TV on (via remote or power button), the screen shows the Vizio logo and the Vizio emblem below the screen starts as a brighter orange glow and dims to a dim orange. The TV refuses to respond to any direct or remote input except for power on and power off (which works both on the remote and on the TV itself).

I've tried unplugging it, holding the power button for 30 seconds and plugging it back in without any noticeable effect. I've also tried entering service mode by pressing Menu, 1-9-9-1 on the remote without any form of response from the TV.

I assume its the mainboard?

[budm]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

How about uploading good clear pictures of the back of the TV so we can see all the boards, and then the pictures of each board so we can get you to do some Voltage testing to help narrow down the problem.

[Kharn]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

I tried a bunch of times to get a good picture of the main board, all the capacitors are flat on the three visible boards.

[patrax]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

This model has power supply cap failures check your voltages on the 12v rail and 5v standby. I assure you it is 95% a psu problem most likely a 10v cap or two is bad. I replace all caps on Vizio psu's everytime they come with straight junk from factory, you were lucky to have gotten the mileage you did. Because the caps are not bulging doesn't mean alot on Vizio boards replace with Panasonic or better.

[Kharn]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

But if there were a PSU failure, would I even get the Vizio logo on the screen?

[patrax]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

Yep it appears that the 5v standby is working which is most generally the case ,but the 12 or 25v side is not because imho of bad caps on the psu. Beleive me 95% of Vizio failure is bad psu caps. Seen it hundreds of times. Check your voltages (if you can), then look at the caps on the psu,sometimes they bulge sometimes not but thats usually the culprit in Vizio lcd's. However if your baclights are working and stay on, and still no response then thats steering towards the mainboard.

[Kharn]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

The backlight works, but it doesn't respond to menu, volume up/down, change source, etc, commands from either the remote or the buttons. All it does is display the Vizio name/logo, it never switches to the last input used (as it would during normal operation).

I have a digital multimeter, but none of the small clips or accessories for it, just the standard probes with ~3/4" tips so I'm leery about poking around in the PSU with them.

[patrax]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

Ok if your baclights are on and stay on its not psu its most likely your main is going out or is already bad. hook up a source and try to get an image if not imho it's mainboard.

[budm]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

"All it does is display the Vizio name/log" are you talking about the the VIZIO logo on the front bezel or it actually shows that on the LCD panel?

[patrax]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

Does it have anything on the screen at all logo/menu? If ur talking nothing on screen at all its def a psu or possible inverter issue. Have u done the "flashlight" test? If u get a faint image with the flashlight test menu/source changes/ anything, its then looking like main or psu/inverter. If ur backlights are on you will know it if you have the back panel off. This sounds like an easy fix most Vizio's are imho, u just have to eliminate the possibles one by one.

[budm]

Re: Vizio VT470M - Vizio logo on-screen, turns on/off but nothing else

If the backligts are on, then you need to find out if the T-CON is getting the switched 12VDC feeding it or not from the main board, or the SMD Fuse on the T-CON may have blown, right now we are clear as to what you are seeing on the SCREEN.