Vizio M651d-A2R won’t turn on

[Hornnumb2]

I can get it to turn on holding down power button for 30 seconds, but if turned off won't come back on. Power board is DPS- 200PP -190 and has 5v standby and 24v. I do get 385v at the long capacitors and none of the caps look bad. When it's powered I don't see any dark spots like bad backlights. Any suggestions to check next. Thanks

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

Seems like a main board issue, aren't the voltages good on power supply?

[budm]

Re: Vizio M651d-A2R won't turn on

But where are the control Voltages readings?

[nomoresonys]

Re: Vizio M651d-A2R won't turn on

Need to test them all, #3 below.

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

Here are the results

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

Let me know if it’s too small and I will type it out.

[R_J]

Re: Vizio M651d-A2R won't turn on

Have you checked the voltages on the LED driver board? also check the fuses on that driver board. I suspect you could have a few bad (likely shorted) led's causing the led driver board to over current shut down. It only takes a couple bad leds and you likely won't see them through the lcd screen.

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

should I be able to unplug the leds and get it to start up?

[R_J]

Re: Vizio M651d-A2R won't turn on

If you unplug the leds, it will likely detect an open circuit and also shut down. The driver board monitors the current the led strings draw and if it is out of the set limit it will trigger a shut down.

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

I haven’t been able to get it back on to test led voltage on board yet, it’s hit and miss when it decides to start up. I did order one of those led tester and get these reading with them unhooked. With the red on pin 1 and ground going down the line 2-4 I get 55.2 and the same going the other way. I will still keep trying to get it to start where I can check those while running.

1: VLED2 +
2: FB2-4
3: FB2-3
4: FB2-2
5: FB2-1
6: FB1-4
7: FB1-3
8: FB1-2
9: FB1-1
10: VLED1 +

[budm]

Re: Vizio M651d-A2R won't turn on

You'll keep black probe of the meter on the chassis, put red probe on pin 1 then turn on the TV to see how high the Voltage jumps up to then wait 10 seconds to see what it goes down to, then turn off the TV and the repeat the same test on the other 9 pins.

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

I am using one of these, right now it won’t start up to test voltage. https://www.shopjimmy.com/sid-gj2c-l...ght-tester.htm

[budm]

Re: Vizio M651d-A2R won't turn on

I am using one of these, right now it won’t start up to test voltage. https://www.shopjimmy.com/sid-gj2c-l...ght-tester.htm

OK, I thought you are testing the LED driver Voltages.
You are trying to test each LED sting with the LED tester.
You will pull the LED connector off the power supply board then out red robe on the connector (that goes to the LCD panel) the VLED1+, then use the black probe to test each FB1-1, FB1-2, FB1-3, FB1-4.
Do the same with LED2+and each one of the FB2-1, FB2-2, FB2-3, FB2-4.
Basically you are testing 8 LED strings.

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

That’s what I did and get the same reading across all sets. 55.2. So does that lead me to believe that if I had a bad led or two some readings would be different?

[budwich]

Re: Vizio M651d-A2R won't turn on

unless there is some thing very "different" in the design, there is something strange with the measured results for pin 11 and 12 (BL) on cn202. Remeasure to ensure that the values are correct. Further look closely at the board / connector to see what the difference is. I would expect any "labelled point" to be the same for the same label.

[nomoresonys]

Re: Vizio M651d-A2R won't turn on

12 looks to be bl-on/off, 11 and 14 don't appear to be labeled.

[budm]

Re: Vizio M651d-A2R won't turn on

Can I see the pictures off the whole backside of the TV showing all the boards?
I looks like the main board is connected directly to the LED driver board so the BL-ON and Dim controls are not routed to the power supply board.

[budm]

Re: Vizio M651d-A2R won't turn on

You also need to do the test on post 11 using Volt meter.

[Hornnumb2]

Re: Vizio M651d-A2R won't turn on

Haven't been able to get to start again yet but her are some photos.

[budm]

Re: Vizio M651d-A2R won't turn on

https://assets.shopjimmy.com/media/c....d01-top_1.jpg
I cannot tell from the picture of the whole backside of the TV to see where CN1 of the LED driver board go to, same for the CN5 of the LED driver board

Picture is not straight shot so it is hard to see which cable to where.
And right now you no longer get any Voltage at VLED1 +, VLED2 + when toggle TV on and off?