Toshiba FireTV image jumps every two seconds. Can it be fixed?

[Lisanimaux]

Hi,
I don't know if someone can help me, but I'm going to give it a try anyway! I made sure to look up my issue before posting, but I couldn't find any thread for this TV model. I should also mention that I never fixed a TV before, please bear with me!

My Toshiba 43LF621U19 REV. B started acting up lately. I tried looking up its "symptoms" online, but I can't seem to find anyone experiencing the same problem, which makes it hard to figure out if this can be fixed and/or which part(s) should be replaced.

The TV was purchased brand new in June 2019. Recently, the image started jumping around every two seconds. The image is fine for two seconds, then starts jumping for another two seconds, goes back to normal for two seconds, jumps again, etc. This normally happens after the TV is on for a while, but it also happens randomly. I can watch TV for an hour before it happens for 20-30 minutes, then it randomly stops and starts again a few hours later.

I posted a video of the issue on YouTube if anyone want to have a look: youtu.be/1HjH31_HVlw


The issue happens when opening the TV, in the “Start” menu, in the “Settings” menu and on any input (ex: DVD player, TV, Netflix). I closed and reopened the TV, restarted it from the settings, went back to factory settings, unplugged and plugged the power cable and unplugged and plugged the HDMI cable. The issue persists no matter what I do, which makes me believe a component is at fault.

From what I read so far, it could be related to the T-con board or its cables. However, since I can't find a video demonstrating the same behaviour, I'm not a 100% sure that's the problem.

I would rather try fixing it then creating additional waste. Thank you, any help would be appreciated!

[nomoresonys]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

See if you can find the backlight setting in picture menu, turn it way down see if anything changes.

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

See if you can find the backlight setting in picture menu, turn it way down see if anything changes.

I turned it all the way down and it doesn't change anything. The screen is evenly lit, it doesn't seem to be the issue.

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

It looks like the issue happens during 30 minutes intervals only. It started around 12:43Pm and just stopped almost exactly 30 minutes later (it's now 1:12PM).

[Diah]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

i think you did the reset from setting menu.. this kind of setting will not help much..
you need to try... inter service menu and from there need to do hard reset

also you need to try clean from both side and re seat the LVDS cable ( the cable connected the main boards to T-CON )

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

i think you did the reset from setting menu.. this kind of setting will not help much..
you need to try... inter service menu and from there need to do hard reset

also you need to try clean from both side and re seat the LVDS cable ( the cable connected the main boards to T-CON )

Thank you! The Fire TV doesn't come with this remote unfortunately, I only have the Amazon Fire remote. I will look how I can access service mode from it. If this doesn't solve the issue, I'll try opening the TV and cleaning the contacts.

[neilc6]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

Likely a bad panel but there is a workaround using the tape cutoff method if you have a tcon board.

https://techhometravel.com/repair-of...lines-on-a-tv/

[nomoresonys]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

Yep, tape-cut-off might work, worth a shot.

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

All right, so I figured out how to do it with the Fire TV remote. However, it's the exact same thing I did a few days ago from the TV menu (they call it "Factory reset" instead of "Hard reset"), which didn't solve the issue. Plus, the image started jumping again while it was rebooting.

I will try cleaning the cable tonight. Is there something I should know before doing it?

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

Likely a bad panel but there is a workaround using the tape cutoff method if you have a tcon board.

https://techhometravel.com/repair-of...lines-on-a-tv/

Thank you, I will try following this tutorial tonight. Hopefully it's salvageable!

[Diah]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

All right, so I figured out how to do it with the Fire TV remote. However, it's the exact same thing I did a few days ago from the TV menu (they call it "Factory reset" instead of "Hard reset"), which didn't solve the issue. Plus, the image started jumping again while it was rebooting.

I will try cleaning the cable tonight. Is there something I should know before doing it?

you have TV Toshiba 43LF621U19 with out RC but you use it as monitor with yours Fire which it plugged via HDMI. ( any things you do with FireTv remote mean this is at the fireTv not the TV self)

unplug the FireTV and change the source to TV signal from the side panel of the TV... call the menu.. let see how it look .. you can upload photo over here via "go advanced"

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

you have TV Toshiba 43LF621U19 with out RC but you use it as monitor with yours Fire which it plugged via HDMI. ( any things you do with FireTv remote mean this is at the fireTv not the TV self)

unplug the FireTV and change the source to TV signal from the side panel of the TV... call the menu.. let see how it look .. you can upload photo over here via "go advanced"

Just to make sure there is no misunderstanding, I'm not using a FireTV Stick. The feature is embed within the Toshiba FireTV, so it can't be unplugged from the HDMI port.

The menu looks the same on every source (HDMI 1, HDMI 2, HDMI 3, Antenna, Composite and Multimedia player). I'm only using HDM1, which is for the TV cable box. The TV is always left on this source. I don't need to change it to access the apps (ex: Netflix, CBC, Amazon, etc.)

Here are two photos of the menu. The first one (press conference) is on HDMI 1/TV cable box. The second one (empty signal) is on Composite. I reset settings on both sources, but it didn't change anything.

[Diah]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

i see... you mean using the smart portal at the tv not the firetv LOL

try to do my suggestion at post #5 before you go to panel.

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

i see... you mean using the smart portal at the tv not the firetv LOL

try to do my suggestion at post #5 before you go to panel.

I tried to do another reset and it changed nothing, so I removed every screw to open the back panel. Wires are connecting the back cover to a board, preventing me from fully removing it. Right now I can lift the back panel approximately 2 inches above the rest of the TV.

I'm sorry if this is a stupid question, but how can I unplug them? I pressed on the white connector and tried to pull it gently, but I'm afraid to break something if I apply more pressure.

I attached a picture of the cable below (sorry for the poor quality):

[nomoresonys]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

Did you try removing your cable box from the equation and just trying a dvd player or game console etc? those plugs are on pretty tight, you just need to lift at the little tab like ends til it comes off, try not to pull by the wires or they could pull out.

[Diah]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

reset only via service menu are really rest to the set.... the one you do its just user setting reset..
you need to mount the set out of wall... put it on table and work .... this is not the cable i am talking about read my post again between (....)

[nomoresonys]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

Did you try a firmware/software update?

[Lisanimaux]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

I apologize for the late reply. Trying to fix this TV has been an emotional rollercoaster!

Nomoresony: Yes, removing the cable box is one of the first things I did. I also made sure the firmware was up to date. Everything was as it should be.

Diah: Are factory reset and hard reset different things? The TV doesn't come with a standard remote, only the FireTV remote. I can perform a factory reset from the TV settings, by pushing on the "Start" button for a few seconds on the TV and by pressing two buttons at the same time on the remote. All three options trigger the "Factory reset" menu. I can't figure out how to do a hard reset without the original remote control.

Here's what I've been doing for the past three hours:
I removed the TV from its stand, unplugged it, removed the screws, unplugged the cables and removed the back. I cleaned both sides of the two ribbon connectors from the T-Con board with a pencil eraser, put them back in place and tested the TV. The image was normal at first, but unfortunately the issue came back after a couple of minutes.

I redid the whole process again, but disconnecte one ribbon cable at the time to figure out which one was at fault. The issue happened almost right away when the right ribbon was disconnected (left still connected). I reconnected it and unplugged the left ribbon instead (right still connected). It's been on for 30 minutes and the problem hasn't happened so far! It seems like we're getting closer to a solution!

I've been watching videos about the tape trick. This one explains pretty well how to block out the clock pins to bypass the signal. However, the terminology on my T-Con board appears to be different. I included a photo below. Are my clock pins located on the right side of the image (underlined in red with a question mark)? If that's the case, are the pins in the same order for both ribbon cables or are they mirrored? I hope I make sense, I'm getting tired haha!

[petehall347]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

am thinking poor solder joint .

[Diah]

Re: Toshiba FireTV image jumps every two seconds. Can it be fixed?

you can use any mobile with IR sender to use apk as RC to your set... also toshiba they have network RC at the market to android devices.. you need to reset the eeprom from service menu first.. before you go to playing with panel.
you got clear image by disconnection one ribbon cable. never mean 100% you have panel and need to block clock signal. remember when your set stay warm more than 30 minute it became stable ... if there panel issue will remain always at same distributed image