Vizio VX552XVT Screen Flashing on and off

[tom66]

Re: Vizio VX552XVT Screen Flashing on and off

You need to test pins A&B on the lone three pin connector. From inspection C is not connected so you can skip that.

Red probe on A or B, black probe on chassis. DC 20V range. Note down readings on both while set operates (with flickering) and when it fails.

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

You need to test pins A&B on the lone three pin connector. From inspection C is not connected so you can skip that.

Red probe on A or B, black probe on chassis. DC 20V range. Note down readings on both while set operates (with flickering) and when it fails.

Thanks Tom66 you are the man! While the screen is on and not flickering the voltage is at A= 1.735v and B= 3.26v. When it is flashing A= 3.34v and I haven't been able to get a reading for flashing B yet because it stopped flashing before i could get a reading. It has not failed on me yet tonight either so I cant get those readings yet. As soon as it does i will get the rest of the readings. Is this helpful at all yet?

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

I believe I just got a reading of B= 2.81 when it was flashing but it was real quick and not steady flashing.

[tom66]

Re: Vizio VX552XVT Screen Flashing on and off

OK, this indicates the main board is causing the flashing.
Can you go into the user setup menu and disable any of the dynamic backlight controls, auto backlight, light sensor, auto picture, etc.

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

OK, this indicates the main board is causing the flashing.
Can you go into the user setup menu and disable any of the dynamic backlight controls, auto backlight, light sensor, auto picture, etc.

I believed I have them all disabled already.

[tom66]

Re: Vizio VX552XVT Screen Flashing on and off

OK, I would then suggest a firmware update, if this TV has USB you can do it via that. You may have to contact Vizio for access to the firmware or it may be on their website.

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

OK, I would then suggest a firmware update, if this TV has USB you can do it via that. You may have to contact Vizio for access to the firmware or it may be on their website.

Ok I will try that. I thought the TV was supposed to update the firmware automatically. I also noticed it gets worse the more the backlight is turned up. Also could you tell me why the picture looks like it does in this picture? I got the TV for cheap off of craigslist hoping to be able to fix in myself. The Backlight in the back panel of the TV seems to be shining through all the holes so i dont think it is a backlight issue.

[tom66]

Re: Vizio VX552XVT Screen Flashing on and off

Huh? Is this the same TV or a different one?

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

Huh? Is this the same TV or a different one?

Same TV.

[Glitcher]

Re: Vizio VX552XVT Screen Flashing on and off

I had a vizio with a flickering problem. I replaced the inverters and it "kind of fixed it" but it still had a slight flicker on screen just not so intense. I then increased the backlight settings on the menu to maximum and the flickering actually stopped.

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

I had a vizio with a flickering problem. I replaced the inverters and it "kind of fixed it" but it still had a slight flicker on screen just not so intense. I then increased the backlight settings on the menu to maximum and the flickering actually stopped.

You replaced the backlight inverter board?

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

Ok i have a new problem now. The TV will be powered on with the vizio logo glowing white, but there will be no sound and no picture and no backlight on. This usually happens after it flashes on and off. I am to the point now where i want to replace the main board, and power supply. But i don't want to waste money if i can isolate what board is going bad. Please Help ME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[tom66]

Re: Vizio VX552XVT Screen Flashing on and off

When the logo turns white test the outputs 5V, 12V, 24V (*if present) from the power supply. If they are missing the power supply is the cause, most likely, though the main board needs to be checked for shorts.

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

When the logo turns white test the outputs 5V, 12V, 24V (*if present) from the power supply. If they are missing the power supply is the cause, most likely, though the main board needs to be checked for shorts.

Those voltages don't read when the screen goes black, though they do fluctuate by as much as 10 volts when it flickers. So you are saying my power supply may be bad? I also noticed when the screen flickers on and off the dark areas sometimes light up briefly. Would this be because of the power supply too? It starting to shut off now after it flickers too much. I also notice if I turn the backlight up it is more likely to flicker on and off and if i turn it down it will slow down or stop.

[tom66]

Re: Vizio VX552XVT Screen Flashing on and off

Yes, just to check you were holding the probes steady on chassis and power supply pin while it flickered? It does sound like a power board issue.

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

Yes, just to check you were holding the probes steady on chassis and power supply pin while it flickered? It does sound like a power board issue.

Thanks so much! Ill replace it and let you know how it goes.

[Ashroyer05]

Re: Vizio VX552XVT Screen Flashing on and off

.

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

So I replaced the power module and the TV is back up and running! The backlight is still dark in some areas of the screen still. I dont think its a screen issue because some parts that were dark before are lit up. There is a red light still flashing on and off on the inverter board. Could the inverter board be at fault or could there be shorts on the main board? Thanks again to Tom66 for all the help!

[tom66]

Re: Vizio VX552XVT Screen Flashing on and off

Most likely, if it looks like that, some of the LEDs in the panel are bad. But does this set use Local Dimming? Or is it global dimming only?

[agent11927]

Re: Vizio VX552XVT Screen Flashing on and off

Most likely, if it looks like that, some of the LEDs in the panel are bad. But does this set use Local Dimming? Or is it global dimming only?

I believe it is local dimming because it does have adaptive lumina. Are the LEDs difficult to replace myself?