TCL 55S451 Stuck on Logo Screen But Working Otherwise

[odie34]

I have a TCL 55S451 that's stuck on the logo screen. I've done all of the traditional troubleshooting steps (power cycling, holding the reset button, etc.), but nothing has worked. I thought the main board was dead, but then I realized that even though it was only showing the logo screen, it appeared to be responding to remote buttons.

So I pressed the reset button again and used the remote to put the TV into screen reader mode. I was then able to navigate through the setup menus (including successfully connecting to the internet) in order to update the firmware. I thought that that might resolve it, but unfortunately it didn't.

A few other bits of information:

• The logo screen begins to fade after a few seconds, and after a couple of minutes the screen is completely black. This doesn't appear to be a screen or backlight issue, as pressing the reset button instantly restores the logo screen.
• Holding the reset button for 30 seconds is supposed to restart the setup, but in my case it simply leaves a blank screen. A simple press of the reset button will cause the logo screen to be displayed.
• A visual inspection shows no indication of a problem. (No burns, bulging caps, etc.)
• I'm a hobbyist whose handy with this stuff, but I have no real training so please be gentle.

I don't see a separate TCon board in this TV, so I'm wondering if that functionality is combined on the main board. If so then perhaps there's still an issue on the main board even though it appears to be working otherwise. I was also wondering if a bad cable could be causing this. (I once had an issue with an external Roku box connected to a TV via a bad HDMI cable. In that case the menus were displayed properly, but the streaming content wasn't displayed at all.)

Any thoughts on next steps? Your input would be much appreciated.

Thanks!

[CapLeaker]

Pictures… pictures… pictures…

[EazyBone]

Try to see if disconnecting one ribbon cable to the screen at a time will change anything. Maybe it will stay on fully if you do that.

[odie34]

Here's a picture of the boards:



I can send close-ups (or remove them and send pics of the reverse side) if anyone needs to see more detail.

FYI, Here's what the screen looks like when I first reset it, then after about a minute, and then after about a minute more...

[odie34]

EazyBone The problem isn't that the logo screen fades. The problem is that the TV doesn't progress past it to the Roku menus.

[EazyBone]

Yea I still wrote what I wrote for you to try it.
TV repair is process of elimination. You have an odd problem where screen fades AND is stuck. So I gave my suggestion. Haven't seen this problem before either but now that we have pictures I would assume main board also. The screen fading doesn't look too much like it's backlights but who knows

[CapLeaker]

Kinds similar what my TCL Amazon TV did. There is a mile long thread if you search my nickname. I heard the startup chime, had backlights, but black screen and it wouldn’t boot.
Problem is to find correct full images. The best version TCL TV to get is the Google TV one as it has most support in the community plus there are a lot of eMMC images available. Firmware updates don’t contain everything. We tried flashing my Amazon TCL to no avail and ended up purchasing a new board for like CAD$65 on eBay and replace it and the TV is still going.

A while later I tried to look at that old main board. Confirmed it being a software issue at Boot. But to lack of Amazon TCL version dumps I junked the board and use it for parts.

It seems to me the TCL’s main boards that don’t have a reset button, have very slim success rate of being fixable.

[Diah]

ROKU / GOOGLE / AMAZOON / ANDROID TV are same shoes source, try to push the Joystick and pull it down the plug in wall socket show us the Recovery menu you got.

[EazyBone]

Kinds similar what my TCL Amazon TV did. There is a mile long thread if you search my nickname. I heard the startup chime, had backlights, but black screen and it wouldn’t boot.
Problem is to find correct full images. The best version TCL TV to get is the Google TV one as it has most support in the community plus there are a lot of eMMC images available. Firmware updates don’t contain everything. We tried flashing my Amazon TCL to no avail and ended up purchasing a new board for like CAD$65 on eBay and replace it and the TV is still going.

A while later I tried to look at that old main board. Confirmed it being a software issue at Boot. But to lack of Amazon TCL version dumps I junked the board and use it for parts.

It seems to me the TCL’s main boards that don’t have a reset button, have very slim success rate of being fixable.

Yea but the TCL roku main boards are like $20 in america. Not even worth flashing an EMMC for that. In canada maybe

[odie34]

ROKU / GOOGLE / AMAZOON / ANDROID TV are same shoes source, try to push the Joystick and pull it down the plug in wall socket show us the Recovery menu you got.

I'm not able to get a recovery menu. To be clear, there is a reset button that I'm able to push, but the screen just goes blank if I hold it for 30 seconds or so. Otherwise all I ever see is the logo screen (which fades out over a few minutes).

[CapLeaker]

Try a firmware update. I remember my TCL didn’t have that recovery menu either. Other than that you need a full dump and flash that.

[odie34]

Try a firmware update. I remember my TCL didn’t have that recovery menu either. Other than that you need a full dump and flash that.

A firmware update is complicated without a screen, but I was able to use the text-to-speech mode to get it done. Unfortunately that didn't help. I was told that the firmware update doesn't necessarily update everything, so it still may be a software issue. Unfortunately I don't have the ability to reflash the entire chip.

[lotas]

If the eMMC is dying or has already died, then no reset, recovery, or update will help; only replacing the eMMC or replacing it with a working motherboard will help.

[odie34]

If the eMMC is dying or has already died, then no reset, recovery, or update will help; only replacing the eMMC or replacing it with a working motherboard will help.

Thanks for the confirmation. I had pretty much come to that conclusion as well. I'm going to get a new main board and let everyone know the result.

[tom66]

eMMC/NAND failure is unfortunately killing a lot of embedded devices. Many times I see the mistake of putting these chips right near CPU since signals need to go that way, but the CPU runs hot and NAND flash hates the heat.

Suggestions for extending the life:
- Keep TV out of direct sunlight if possible
- Consider adding a fan to the mainboard area if possible
- Turn off smart standby features. TV might take longer to boot up but will wear chip less
- Uninstall background services where possible, if it runs Android

[CapLeaker]

I am just about willing to bet, that there is nothing wrong with the EMMC.

[lotas]

I don't know if it's expensive or not, but they're selling a motherboard for your TV.
https://www.ebay.com/itm/266554778927

[lotas]

I am just about willing to bet, that there is nothing wrong with the EMMC.

No one is arguing here, this is just a guess, it could be the SoC that is faulty via HDMI or LAN port, or maybe the RAM... here you need to connect to UART and look at the boot log to see where the problem is occurring.

[CapLeaker]

No one is arguing here, this is just a guess, it could be the SoC that is faulty via HDMI or LAN port, or maybe the RAM... here you need to connect to UART and look at the boot log to see where the problem is occurring.

Absolutely agree, lotas.
I just remember my TCL we tried to fix.