Strange HDMI problem with Vizio M3D421SR

[twoj]

I have been trying to troubleshoot my M3D421SR. Its been good for ~3years. Few days ago the signal from BluRay and Xfinity cable box over HDMI connector (does not matter which) do not display anything on the screen and I get 'Not Support!' message with the BluRay. The strangest thing is that when xFinity box boots up, I can see 2 low res screens that it shows while booting. One is 480 and the other 720. My TV reports that in the upper right corner.

However my laptop, has no issues rendering 1080 screen on the same HDMI ports. I also tried different cables, 4 of them, same problem. None of them work with BluRay and Xfinity, but no problems with my laptop.

Component connections work fine as well, and so does Netflix via smart apps?

I tried doing the 'soft' reset with pulling the power cord out, and holding the the power switch down. No success. I also did the factory reset via the menu. No dice.

I have contacted the ebay rebuild service, but they said that there is nothing to fix since I still had no problem displaying other signals on the screen.

I'm suspecting a handshake problem between protected HDMI devices and the TV.

So, I tried to get a new mainboard, by the one I need: TXBCB2K00603Q is nowhere to be found; so I ordered TXBCB2K00605Q instead.

And this is when I found this forum!

So my real question are:
1) Is mainboard replacement the only way to fix this TV?
2) Can I safely try using TXBCB2K00605Q instead of TXBCB2K00603Q?

I appreciate you time and help.

Regards

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

wrong post

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

did you try a reset? Use the Arrow buttons on the remote to highlight CLEAR MEMORY/FACTORY DEFAULTS or Reset TV to Factory Defaults and press the OK button. Enter the parental control PIN (if you have never changed this, it is 0000) and press OK on the remote. Do not press the Power button.

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

https://www.youtube.com/watch?v=HSPI5LoVLhw

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

Yes. I tried that no success. I also wiped out my apps :-) just to be sure.

[ReeceyBurger123]

Re: Strange HDMI problem with Vizio M3D421SR

I have this with a toshiba 32av55d (or somthing) cant find out whats causing the issue, tried new epprom all the regulators that run the hdmi are fine no badcaps. Swapped out the mainboard and all works I have come to the conclusion that one of the vga chips on the board have failed.

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

But, why would my laptop work over the same HDMI ports? It has to be something with the 'protected' vs open HDMI signal right? So then it has to be a problem with decoding hardware?
Either way mainboard replacement is the way to fix it. How about the different mainboard #'s; Should I worry about that?

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

maybe try a firmware update, if ones available.

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

No firmware available. No other internal diagnostics available either.
You can check the status of the current screen via 'INFO' function. And it does report that there is something there, giving you the resolution of the signal coming in.

STRANGE ?!?

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

if I understand correctly, your laptop works on the same hdmi tv ports, then I cant see how its a mainboard issue.

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

can you set your tvs hdmi settings to all resolutions?

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

No I can not, they are auto sensing/detecting.

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

try unplugging all video connections, unplug tv for 15 minutes, plug it back in plug one hdmi source maybe blueray, nohing else, then turn tv on, dont turn tv on before you plug bluray hdmi in, see if that works.

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

if I understand correctly, your laptop works on the same hdmi tv ports, then I cant see how its a mainboard issue.

Well, other components work correctly. The only problem is the HDMI when it receives a 'protected' or 'encrypted' HDMI signal (I'm speculating here, and could be wrong). At least this would explain why my laptop works. So it this is the case, whatever component actually performs the decryption is faulty.

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

try unplugging all video connections, unplug tv for 15 minutes, plug it back in plug one hdmi source maybe blueray, nohing else, then turn tv on, dont turn tv on before you plug bluray hdmi in, see if that works.

OK... Give me 16 min.... :-)

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

then maybe just try xfinity by itself, or if the above works, try adding xfinity, read something about hdmi dont like being plugged in while tv is on.

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

OK... Give me 16 min.... :-)

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

OK. Did that. And no display. Just black screen. TV says 'Retrieving Data...' then flashes resolution @ '1080' and screen stays black. You can see backlight on, so its getting something.... but no real picture

[nomoresonys]

Re: Strange HDMI problem with Vizio M3D421SR

something strange for sure, maybe call xfinity tech. support.

[twoj]

Re: Strange HDMI problem with Vizio M3D421SR

something strange for sure, maybe call xfinity tech. support.

Yes. Thought of that, but if my BluRay stopped working at the same time, it can not be xfinity problem exclusively. That is why I'm pointing to 'encrypted' HDMI vs clear HDMI signal. Can someone else who know their stuff disprove this?

I thought it was 1080 problem, so I kicked down xFinity + BluRay to 720 with NO success. And I can render 1080 screen from my laptop! Frustrating!