Vizio m550vse stuck on with V on screen

[irad]

When turned on the V appears on the screen and can not be turned off with remote or button on tv. I have powered off the tv, left it unplugged overnight. I opened up the tv and the power board has the correct voltages. I then read the posts on testing voltage regulators and tested mine. They are all fixed voltage, LD1117ag. The 3.3v ones read 3.26v and 3.27. The 1.2v ones now read 1.16 and 1.17. They did read 1.12 the day before. I did an experiment. I attached an ethernet cable and tried to power up the tv. I attached the tv to a power strip. I toggled the power strip on and off twice in the span of 1 second. Then pressed the on button. The V appeared on the screen and after 12 seconds I can use the tv. I think it took firmware updates, while I watched a channel. I did a factory reset and the tv continued to work for hours. The next day,today, I was back to freezing with the V on the screen. I toggled the power strip twice in a second and the tv worked. Any ideas on what to do? Should i change the 1.2v voltage regulators? Should I change the 3.3v regulators? How should i proceed?
Thanks, Ira

[irad]

Re: Vizio m550vse stuck on with V on screen

I checked all the caps on the power board with an esr meter. They all tested good. I checked the output voltages on ac volts looking for oscillation and got a maximum of 0.08 VAC. I reflowed a few chips and nothing changed. The only thing I see is that the 12v coming off the power board is at 11.83v.

[Nick's Tvs]

Re: Vizio m550vse stuck on with V on screen

Logo stuck on screen sounds like a bad EEPROM.
Physical movement making a difference however indicated a physical issue such as bad solder joints.

[ljintexas]

Re: Vizio m550vse stuck on with V on screen

I agree with Nick on the EEPROM...I have had two Vizios with that malady. Both were main board issues. Found out later that one took a lightning strike to the dish/coax. Main board fixed them both. I have also found plenty of suspect solder joints on Vizios, among others.

[irad]

Re: Vizio m550vse stuck on with V on screen

I'll look for bad solder joints, since I can get the tv to work if I toggle the power strip, the tv is plugged into, twice quickly.

[Steve_Rogers_1970]

Re: Vizio m550vse stuck on with V on screen

I know this is an old thread, but thought i would take a chance. similarly, every so often, i can cajole this TV to come on. if i leave it powered up, it stays working. if i power off for more than a minute or so, i'm back to this symptom. The limited research i've done tells me there isn't an EEPROM on this. could that be true? if there are cold soldier joints, any suggestions where i can look to touch them up?

[dskall]

Re: Vizio m550vse stuck on with V on screen

Try heating main processor on mainboard and see if that allows it to come on.