Vizio D65x-G4 Volume changes on its own

[karthur]

On this Vizio D65x, the volume will change on its own. I don't mean like during commercials where the volume will increase. I mean its like the (+) volume button on the remote is pressed and the actual volume dialog is displayed on the screen going up. It will do this, then the volume may start going down. It might go all the way to "0"or it might stop at a different number, then start going back up. The whole time its doing this, the volume dialog is shown on the screen.

It wont do it until it has been "ON" for 20 or 30 minutes, so it does seem to be heat related.

I thought it might be my remote, but I removed the batteries from the remote and it still does it, so I don't think that is what it is. I am using an Amazon Firestick, but I use the same firestick on another TV without issues.... so I really don't think its the firestick.

There is a circuit board for the IR control, YX-PCB-KEY-277 Key Controller board that I thought might be the issue. Or, I guess it could be the main board.

Would there be anyway to test to make sure which is the culprit before I start tossing parts at it?

Thanks

[lotas]

So turn off the control board and see if the volume changes or not.

[m1ch43lzm]

Hi, I'm not an expert on TVs, but I think it may be faulty/dirty buttons, as in they have resistance across them when not pressed
Try turning on the TV then unplug that button board with the tv powered on, see what happens

[lotas]

If you don't want to end up with a dead processor, then all manipulations with disconnecting and connecting different cables, cables under voltage, then you must first de-energize the TV from the outlet and then disconnect and connect the cables!

[nomoresonys]

Maybe try removing the button board and putting a little iso alcohol on those 4 tactile push button switches and push them multiple times. It may clean/free it up if that is the issue. It does dry fast but let it dry a while before trying again. Can check those resistors and any cap that you see on it too.

[karthur]

Thanks for those suggestions. Before pulling any boards or connections, I played around with it more this afternoon. Now when I press the remote Volume (+) button, the volume on the TV starts going up and up. If I don't touch any buttons on the remote it will go all the way to 100. But if I touch any other key, say the number "2" key, then it stops. I can press the Volume (-) button and it will go all the way to 0. But if I touch any other button it will also stop as before.
Also when I go into the TV Settings menu, if I press the arrow down button, it will scroll through all the menu items and stop at the bottom. Rather than going down one menu item, it just keeps going like I am pressing the button multiple times. Same thing if I press the arrow up, it scrolls all the way to the top. But if I quickly press a number button it will stop on one of the menu items.

I did try a known good Firestick and I get the same weird issues.

I am now leaning toward it being the main board rather than the Key Controller Board.

Thought/suggestions?

Thanks

[Diah]

you are playing with Remote Control, what about if this RC defect !!, take out the batteries from the RC ( to put it out 100% ) and use the TV direct control ... let see if this issue remain or not

[SMDFlea]

Check the volume buttons on the back of the TV , had a similar issue with a toggle button on a toshiba TV, i thought it was the remote at first. A quick spray with contact cleaner solved it.

[lotas]

Just disconnect the cable from the control buttons and check....

[nomoresonys]

Well if its just the remote fkin up, take it apart and clean the board with iso alcohol, about 2,001 how to videos on youtube.

[nomoresonys]

Can try the lazy way, take batteries out hold power button down for 59 seconds and push all the buttons 42 times before putting batteries back in and make sure batteries are new.

[karthur]

I took the batteries out of the remote so its totally out of the equation. I have 4 buttons on the back of the TV. Power, (+), (-) and Input. I press the power button and the TV comes on, but then the volume starts going up and up.... all the way to max of 100. Now pressing any of the buttons does not change anything on the TV. It wont even power off when I hold down the power button. To power it off, I have to unplug it.



I did check the continuity of the button switches on the Key Controller Board. They seem to be working correctly. I am going to say its the main board. Maybe a cold joint somewhere or maybe a flaky component.

[nomoresonys]

Maybe try this: https://www.youtube.com/watch?v=u9t1-pzT-Ps

[nomoresonys]

Check if you have an auto volume setting, if so set it to off or normal and retry. Maybe turn off any cec settings.

[SMDFlea]

I took the batteries out of the remote so its totally out of the equation. I have 4 buttons on the back of the TV. Power, (+), (-) and Input. I press the power button and the TV comes on, but then the volume starts going up and up.... all the way to max of 100. Now pressing any of the buttons does not change anything on the TV. It wont even power off when I hold down the power button. To power it off, I have to unplug it.

I did check the continuity of the button switches on the Key Controller Board. They seem to be working correctly. I am going to say its the main board. Maybe a cold joint somewhere or maybe a flaky component.

Post a picture of these 4 buttons, are they like the ones in the picture that lotas posted. Did you check the exact resistance across each of the buttons when pressed and not pressed (with the TV unplugged)

Edit: Did you test voltage across the pins

[lotas]

There may be a leak inside the button between the membrane and the contact pad, as the silver-plated layer on these contacts turns black and this oxide begins to create internal resistance, causing false button operation....
And if at least one button is pressed or has some internal resistance between the contacts, then the others will not work...

[EazyBone]

You probably tried this already.. but ive fixed this before doing a factory reset and an update. May not help but you never know

[R_J]

Do as recommended in post #9. one of the tac switches is bad on the button board, you can't check it with a meter. you will likely need to have the button/ir board connected to turn on the tv, so push the power and immediately disconnect the button board.
search D65x-G4 Vizio Key Controller Board 20180628

[nomoresonys]

Nope, not familiar with the seller, is just the cheapest I see: https://www.ebay.com/itm/33331618157...Bk9SR5y_xc7pZQ

[EazyBone]

I've bought from them, never had a problem.