Vizio M50-C1 - it turns on then turns off

[aoshi]

Hi,

I'm new to the forum. I'm having an issue with my Vizio M50-C1. I plug it in, power indicator on lower left side lights up then turns off which is normal when first plugged in. I press the power button, power indicator lights up, Vizio logo shows up on screen, then turns off after 3 secs. I see a faint light on the power indicator after it turns off. I got the white LED power indicator like this but doesn't fade completely off.

https://support.vizio.com/s/article/...language=en_US.



Power button does nothing. If I leave it plugged, it will power up after a minute and shows up the vizio logo screen then turns off again. This will cycle continuously.

I had the tv unplugged for several days then tried again and was surprised it work for about 30 mins before the problem happened again.

Hopefully some can help me on this. Not sure if it is the main board or the power supply.

[dskall]

Re: Vizio M50-C1 - it turns on then turns off

Need good clear straight on pictures of back of tv with cover off and each board.

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

I figure I need that. I'll be doing that in a bit when I get back. I tried to look for signs of bad capacitors and found none. Thanks

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

Here is what I got. Got a multimeter to test.

[dskall]

Re: Vizio M50-C1 - it turns on then turns off

And also Need voltages from connector that goes from power supply board to main board. Will need pin#- PIN DESCRIPTION -Pin voltage in standby-Pin voltage when pushing power button and picture of connector on power supply board.
Format:
Pin# - Pin Description - Pin Voltage standby - Pin voltage power on
1 - XXXXXXX - XXv - XXXv
2 - XXXXXXX - XXXv - XXXv
3 - XXXXXXX - XXXv - XXXv
4 - etc.

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

Pin 5V - 5.15V - 5.17V
Pin 12V - 19V - 19.1V
PS ON - 0.009V - 3.69V
DIM - 0.002V - 3.13V
ON/OFF - 0.002V - 3.3V
Pin 24V - 0.001V - 22.15V

Pin 24 V goes to the board on the middle not on the main board.

[dskall]

Re: Vizio M50-C1 - it turns on then turns off

12v pin is 19v?

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

Just got off from work. But yes, 19V on the 12 V pins. I double checked it. There where 6 pins that says 12V and all had 19V. Is it a bad power supply?

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

Tried testing the power supply board without the wiring to the main board. The 12V pins still shows 19.1V. Looks like a bad power supply. Hopefully someone can guide me on how to test for bad components for the power supply board.

[dskall]

Re: Vizio M50-C1 - it turns on then turns off

I saw another post were they had 19v so maybe mismarked

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

I see. How about the 22V for the 24Vpin? Is that ok? Would it then be the main board?
Read some posts that this might be bad EEPROM.

[dskall]

Re: Vizio M50-C1 - it turns on then turns off

You get no flash of backlights at all?

[dskall]

Re: Vizio M50-C1 - it turns on then turns off

Sounds like eeprom. I saw no eeproms for that board

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

I do get the backlights on. Screen would turn on then the vizio logo appears on the screen, before it would turn off.

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

I was able to turn it on again by several tries of the power cycle (unplugged then hold power button. Did a factory reset. Finished with the setup then having that same problem again. Turn on -Vizio logo displays - Turn off - then would turn on again after about 2 mins. Like it can't load its firmware. I'm not sure if its already a bad main board or just a bad firmware or something. Hoping for some other suggestions. Thanks

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

I got it turned on again. A thing that I noticed is that the power indicator light is very faint. I remember this should be bright when turned on. It became unresponsive after some time and had to unplug. Went to the same loop process again. Is 22V low for 24V pin?

[dskall]

Re: Vizio M50-C1 - it turns on then turns off

What dcv do you get across C9804 main cap on power board when it tries to power on? I don't think 22v is the problem. May have some bad caps on main board.

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

Thanks man. Just checked and its 395V. Tried looking at the main board and not seeing any bad caps that I can notice. I tried removing it and looks like it has some adhesive that I cant pull it out. You think that its ok to pull it out to check the whole main board?

[aoshi]

Re: Vizio M50-C1 - it turns on then turns off

I got some time today and got the main board out. There's no signs of bad capacitors on the main board that I could notice. How would I be able to test it? Would I need to solder it out to test? Any other suggestions on components that I would need to check out?

Thanks