Vizio E321VL needs on-off-on cycle for backlight to work

[Dweezil]

Hello all,

Thanks for taking the time to look at my question.

My Vizio E321VL needs a double power-on to work. I need to turn it on, then off, then on again for the backlight to come on and stay on. Here's the behavior:

1. Turn TV on Backlight comes on for about a second and goes off.
Audio working, and video signal is there as well - can
see the picture very faintly from room light. TV functions
well as a radio at this point.

2. Turn TV off.

3. Turn TV on again, and it works correctly, backlight stays on. Can watch
TV for hours, it's all good.


It has behaved like this for over a year. I bought it refurb (now I know why it was returned), and I didn't notice it in time before the short warranty expired, so I've just lived with it.

Any suggestions? Anything to try before meter and scope?


Thanks!

[johnboy1313]

Re: Vizio E321VL needs on-off-on cycle for backlight to work

Is it a quick ON-OFF-ON or do you turn it on, let it sit, turn it off, and then back on?

Is it just ON-OFF-ON everytime, or sometimes does it take a few times to get it to come on?

Is this just when using the remote, the button on the unit, or either one?

[ecking767]

Re: Vizio E321VL needs on-off-on cycle for backlight to work

I will buy a soldering iron and a roll of solder. You can start by re-soldering connections on the power supply board. you may have a cold solder joint some where. Check the inverter high voltage side for cold solder joints and the 24+ volts caps for cold solder joints.

Since the your TV power on after a few tries tell me there is a cold solder joint some where.

Also once your TV power on and stay on, you can check you voltages on the power supply and main-board.

[Dweezil]

Re: Vizio E321VL needs on-off-on cycle for backlight to work

Johnboy - Sequence is: ON, let sit(boot, really) for a couple seconds, turn off after hearing audio. As soon as the VIZIO light goes dark (another second) turn it back on. Always works this way, never have to do it more than once. Remote or power button on the TV. About every 25th time, the TV only requires the first power-on, i.e. works properly.

Ecking - Once upon a time I fixed a tube TV by reflowing all the joints in the high voltage section. I might have to give that a try.

Weird part is it doesn't "feel" like a cold joint, because of the very predictable behavior. I never have to power cycle more than once. Never know until I get in there, I guess.


Thanks!

[johnboy1313]

Re: Vizio E321VL needs on-off-on cycle for backlight to work

The only similar experience I've had was a bad capacitor, but it got worse with time. Meaning it took more effort to finally get it to work properly. I was leaning toward cold joint too, but the use of the remote and the short timespan point elsewhere. Possible EEPROM issues maybe? May be time to open it up. If it were me, I would turn it on the first time and check the voltage regulators on the main board while there was no picture and then get the picture to come on and check again.