Vizio M261VP Not Turning On

[SBlevins]

Hi, guys. I have a problem with my Vizio LED TV, model: M261VP

Currently the TV will attempt to power on and the power light blinks white for ~30 seconds, and then the light turns on for a few seconds and then the TV powers off. Nothing appears on the screen and the backlight does not turn on either. No sound is audible.

I found this, but I do not know where that capacitor is. All of the capacitors seem solid, and not bulging. If it is a tiny one, where to find a replacement:

I thought I would post a progress update on diagnosing no video problem in case anyone has the same problem in the future. I removed what I thought was a shorted Schottky diode from the video display board power supply. To my surprise The short was still in the circuit. the diode checked ok. So after more diagnoses I determined bypass capacitor C71 on the display board (t-con) was causing the problem. Removed the capacitor from the circuit and the short disappeared. Reassembled the set without the bypass capacitor and I now get video. The video however is flickering and producing some black horizontal lines. The missing capacitor may be causing to much ripple in the power supply or there may be another problem yet to be discovered.

I thought that the issue might just be the LED panel had gone bad, as noted in another thread (see below), but I tested every LED, and the connections seemed solid.

i have seen many of these units having backlight issues and in my experience a lot of them have been bad soldering on the connector right on the board with the led's on it...in order to repair u need to dismantle entire set down to getting led strip out...with it still taped to metal and resolder the actual connector pins back to the board( sometimes u can see that the connector is actually shifted off to one side) hope this helps

Anyone have any ideas of how to proceed? I have searched Google extensively and the only thing that seemed to work for some people was the LED panel but mine seems fine in terms of the connections.

Special Notes:
-LED TV, all 84 are able to be lit externally
-External Power Adapter (19V, 4.74A)
-2 Years old
-Internet capable (if useful?)
-Special Reset Tried (Power button 30 seconds while off)

See link for High Res Image:
https://dl.dropboxusercontent.com/u/...9/DSC_0207.JPG
https://dl.dropboxusercontent.com/u/...223_101829.jpg

[nomoresonys]

Re: Vizio M261VP Not Turning On

guess a good place to start, would be look your power supply board over real good, check any part labeled F, F=fuse, test fuse with tv off and unplugged, test in diode mode, lead on each end, should read 000 or close to it, if read ol or no change, prob. bad fuse.

[nomoresonys]

Re: Vizio M261VP Not Turning On

are there any lights on front at all, power on standby etc, when it shuts off are any lights still on?

[SBlevins]

Re: Vizio M261VP Not Turning On

are there any lights on front at all, power on standby etc, when it shuts off are any lights still on?

I checked the fuses I could find, and they all seemed okay. The main power light in the front lights up, and then blinks about thirty times, and then stays on for a few seconds but then cuts out. It then turns on and does the same thing again. No other lights blink or turn on.

Also, one of the fuses I found said F9, and then there was F8 and F1. Does that mean that there is another 6 fuses that I have not found?

[SBlevins]

Re: Vizio M261VP Not Turning On

I tried plugging the TV back in again, and after that whole cycle with the main power lights, I heard a barely audible click, and then the lights turned back on and did another cycle. Could that just be the TV being re-energized, or possibly a source of the issue?

[nomoresonys]

Re: Vizio M261VP Not Turning On

I checked the fuses I could find, and they all seemed okay. The main power light in the front lights up, and then blinks about thirty times, and then stays on for a few seconds but then cuts out. It then turns on and does the same thing again. No other lights blink or turn on.

Also, one of the fuses I found said F9, and then there was F8 and F1. Does that mean that there is another 6 fuses that I have not found?

thats prob. all of them if you looked real good.

[nomoresonys]

Re: Vizio M261VP Not Turning On

I'll check for a manual.

[nomoresonys]

Re: Vizio M261VP Not Turning On

didnt see any manuals for that model.

[nomoresonys]

Re: Vizio M261VP Not Turning On

can you read the pinouts on the power supply board by the cables going to the other boards?

[nomoresonys]

Re: Vizio M261VP Not Turning On

should be labeled with some voltages.

[SBlevins]

Re: Vizio M261VP Not Turning On

didnt see any manuals for that model.

Does that mean that I am kind of out of luck? The only similar model I know of is the M260.

[nomoresonys]

Re: Vizio M261VP Not Turning On

check post 9 and 10 above.

[SBlevins]

Re: Vizio M261VP Not Turning On

check post 9 and 10 above.

I do not see any voltages. The power supply is external serving 19V to the main board, and then the connection to a longer one that exists near the actual LCD has a ribbon cable, but no voltages that I can see.

Pin numbers, and that is about it, aside from a voltage on the IR receiver sensor board.

[nomoresonys]

Re: Vizio M261VP Not Turning On

its tough without a manual, if we had a manual, could check expected voltages at connector plugs of main board, aka the cables going out to the rest of tv.

[nomoresonys]

Re: Vizio M261VP Not Turning On

maybe we can get a hand from 1 of the pros, fingers crossed.

[CapLeaker]

Re: Vizio M261VP Not Turning On

oyyyyyyyy... there are a few voltage regulators to check and so many small switching power supplies, it makes my head spin. I think the voltage difference between the regulators pin in and out should be 1.2V. The tab is positive out and joint with the center tab. The left pin should be voltage input and the right pin is the adjustment.
Does it attempt to turn on the backlight at all? Unplug the backlight and see what that does.

[SBlevins]

Re: Vizio M261VP Not Turning On

oyyyyyyyy... there are a few voltage regulators to check and so many small switching power supplies, it makes my head spin. I think the voltage difference between the regulators pin in and out should be 1.2V. The tab is positive out and joint with the center tab. The left pin should be voltage input and the right pin is the adjustment.
Does it attempt to turn on the backlight at all? Unplug the backlight and see what that does.

I tried removing the cable to the backlight, and it just does the same thing.

[CapLeaker]

Re: Vizio M261VP Not Turning On

Measure those voltage regulators on the top right corner (I think they are U9 and U10). These VIZIO sets are known for failing regulators on main boards and bad soldering anywhere. You may have a short in the LED backlight wiring or a burnt out LED, who knows, but that wouldn't surprise me at all. First we got to figure out if the backlight would get some juice or not.

[SBlevins]

Re: Vizio M261VP Not Turning On

Measure those voltage regulators on the top right corner (I think they are U9 and U10). These VIZIO sets are known for failing regulators on main boards and bad soldering anywhere. You may have a short in the LED backlight wiring or a burnt out LED, who knows, but that wouldn't surprise me at all. First we got to figure out if the backlight would get some juice or not.

I checked all of the LEDs in diode mode and they all lit up with my multimeter.

Okay, so I measured the voltage regulators and what was labeled as U10 did not look like U9. See image:

https://dl.dropboxusercontent.com/u/...69/Circuit.jpg

-U9 to carry about .25V
-U10 to carry nothing, based on the pins I measured.
-U8 carried 18.5 V

[budm]

Re: Vizio M261VP Not Turning On

OK, the info on 3-pin Voltage regulator 1117 series:
Looking at it with the big tab (internally connected to the center pin pin2) up.
The left pin is GND if it is fixed output regulator, if it is ADJ output then the Voltage between this ADJ pin and the output pin (center pin/big tab) should always be 1.25V.
The right pin is the Input pin.
The out put Voltage of the ADJ regulator will be = to the Voltage on pin 1 and circuit ground + 1.25V.
So please take the readings and report the result in the format as shown in this thread:
https://www.badcaps.net/forum/showthread.php?t=22231