Vizio M75-c1 - no power, no lights, boards replaced

Question

Vizio Television

Repair guides and support for LED, LCD, HD and other Vizio TVs.

crwdns2934591:020crwdne2934591:0 crwdns2934593:0crwdne2934593:0 | crwdns2947278:03crwdne2947278:0 crwdns2947270:0crwdne2947270:0

Steven W @stevenw14535

crwdns2934065:0crwdne2934065:0: 13

2

crwdns2931729:0crwdne2931729:0: Nhl 3, 2024

crwdns2933897:0crwdne2933897:0

Vizio M75-c1 - no power, no lights, boards replaced

So for We have replaced 2 power supply boards and have repaired the main board. I still cannot get the TV to turn on and I am not aware of where I can find a schematic to be able to check voltage on the wires and ports. I'm sure that this TV was affected by a power surge but I am not getting any standby light after taking the back of the TV off on the main board even after replacing the two power boards and having the main board repaired. Has anybody seen this before and if so could you point me in the direction of either a schematic or a solution. This would be greatly appreciated.

(Replaced in pic above)

(Repaired in pic above)

Added pics of connectors

Here is the connector on the smaller board

Here are the connectors on the next board

Here are the connectors on the remaing board

Below are the video and pics of the main board

Complete picture

Video

Path of wires from power boards

Diagram

board under sheet metal

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0

crwdns2889612:0crwdne2889612:0 1

crwdns2944067:09crwdne2944067:0:

just a high level view of diag on this. check the voltages from the power supply on the output. if they are present and stable, check for the voltage on the input to the mainboard. if the voltage is not there, still a power supply issue. if it is there, check the voltage from the mainboard to the tcon board. if the voltage is not there, still a mainboard issue. if it is, further testing will be required.

crwdns2934271:0Nhl 16, 2024crwdnd2934271:0 jostewcrew crwdne2934271:0

@jostewcrew, I posted a drawn out diagram with some readings.

crwdns2934271:0Nhl 20, 2024crwdnd2934271:0 Steven W crwdne2934271:0

@jostewcrew, was that sufficient?

crwdns2934271:0Nhl 23, 2024crwdnd2934271:0 Steven W crwdne2934271:0

@stevenw14535, good start on the diagram. keep going. from the looks, the power board is carrying the voltage through from power board a, to power board b. there are many boards it goes to from there. as requested, check the input from the powerboard to the mainboard and see if the voltage remains present. if not, still power supply issue i suspect. if so, check the mainboard output to the tcon input. this will start getting us all honed in a bit. also @oldturkey is on the job it seems, his knowledge far surpasses my own. keep checking the voltages and add to the diagaram. it will let us know where the voltage stops and we can get started.

crwdns2934271:0Nhl 23, 2024crwdnd2934271:0 jostewcrew crwdne2934271:0

@jostewcrew where you been hiding for the last 4 years :-) ? Welcome back

crwdns2934271:0Nhl 23, 2024crwdnd2934271:0 oldturkey03 crwdne2934271:0

crwdns2934275:04crwdne2934275:0

crwdns2934285:0crwdne2934285:0

crwdns2933313:01crwdne2933313:0

just a high level view of diag on this. check the voltages from the power supply on the output. if they are present and stable, check for the voltage on the input to the mainboard. if the voltage is not there, still a power supply issue. if it is there, check the voltage from the mainboard to the tcon board. if the voltage is not there, still a mainboard issue. if it is, further testing will be required. — jostewcrew
@jostewcrew, I posted a drawn out diagram with some readings. — Steven W
@stevenw14535, good start on the diagram. keep going. from the looks, the power board is carrying the voltage through from power board a, to power board b. there are many boards it goes to from there. as requested, check the input from the powerboard to the mainboard and see if the voltage remains present. if not, still power supply issue i suspect. if so, check the mainboard output to the tcon input. this will start getting us all honed in a bit. also @oldturkey is on the job it seems, his knowledge far surpasses my own. keep checking the voltages and add to the diagaram. it will let us know where the voltage stops and we can get started. — jostewcrew
@jostewcrew where you been hiding for the last 4 years :-) ? Welcome back — oldturkey03

score 0 · Answer 1 · 2024-10-03T18:37:50-07:00

oldturkey03 @oldturkey03

crwdns2934065:0crwdne2934065:0: 818crwdns2936485:0crwdne2936485:0

1.2crwdns2936485:0crwdne2936485:0

924

2.4crwdns2936485:0crwdne2936485:0

crwdns2931729:0crwdne2931729:0: Nhl 3, 2024

crwdns2933897:0crwdne2933897:0

@stevenw14535 schematics for Vizio's are pretty much non-existent. You can find some of the old ones but nothing within the last 8-10 years. Since they are using a hodgepodge of boards, you may have better luck by trying a search based on the board numbers, not by the TV model.

You've said you "repaired the main board" but forgot to tell us what you fixed on it. You will also have to find out if you have any power coming to the power board. The TV's standby power comes exclusively from the power board, but it is the main board the tells the power board what to do with it. Since you do have new power boards, my prime suspect is the main board (possibly our IR board but unlikely). There may be more that needs to be fixed.

Post some good pictures of all of your boards with your Question. Those will have to be well-focused and large enough so that we can zoom in on those without losing sharpness :-)

Adding images to an existing question

update 10/25/2024

need to check the fuses on here as well

crwdns2934105:0crwdne2934105:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0

crwdns2889612:0crwdne2889612:0 0

crwdns2944067:035crwdne2944067:0:

@oldturkey03, I sent off to a repair shop and they responded that they repaired and tested the main board. I uploaded pictures to the question.

crwdns2934271:0Nhl 3, 2024crwdnd2934271:0 Steven W crwdne2934271:0

@stevenw14535 have you checked for power to the fuse once your TV is plugged in? Next I'd check for power on the rectifier(s) and see if you have AC as well as DC. Now, don't just be poking around that board with your meter. The board has to be plugged in, so there will be power on it (how much depends on your household voltage) If you are new to this, don't. wait until somebody can help you out with it :-)

Looks like you got a couple of other boards connected to the power board. Post some pictures of all of those boards and how they connect. Is the 715G6887-P01-004-002M the only power board you replaced?

crwdns2934271:0Nhl 3, 2024crwdnd2934271:0 oldturkey03 crwdne2934271:0

@oldturkey03, I did check the fuses with it plugged in and there was voltage. I have not checked the recifier. I will update pictures of which one were replaced.

crwdns2934271:0Nhl 3, 2024crwdnd2934271:0 Steven W crwdne2934271:0

@oldturkwy03, Pics updated

crwdns2934271:0Nhl 4, 2024crwdnd2934271:0 Steven W crwdne2934271:0

@stevenw14535 what does your Vizio have going on there? Looks like you have multiple power boards. I see three. You have checked all of those for any power? WE really need to see good close-ups. In particular the cable connectors and the legends on those. That way we know where and what to measure.

crwdns2934271:0Nhl 4, 2024crwdnd2934271:0 oldturkey03 crwdne2934271:0

crwdns2934275:030crwdne2934275:0

crwdns2934285:0crwdne2934285:0

Vizio Television

Vizio M75-c1 - no power, no lights, boards replaced

crwdns2933313:01crwdne2933313:0

crwdns2934229:0crwdne2934229:0