Question Hisense 50k23dg vertical lines

[Schepc]

So I have a Hisense 50k23dg and initially it wouldn't turn on but had sound. Did flashlight test and seen picture so I removed screen and found a couple burnt LEDs. Replaced all LEDs and now when I turn on I get a blue screen that has vertical white lines that move across the screen. Eventually if left on the lines will change colors to multi colored lines and stop moving. Fills the entire screen. Just fyi I did do a voltage test on xp805 on the power board and I'm getting 19v on pin 10 and 9 instead of the 16v the board says. Pin 7 I get 3.3v pin 4 I get 4v, 5 on pin 3. All the other pins were what the board says. These are reading with the tv plugged in and power button on

 

[RinusB]

So I have a Hisense 50k23dg and initially it wouldn't turn on but had sound. Did flashlight test and seen picture so I removed screen and found a couple burnt LEDs. Replaced all LEDs and now when I turn on I get a blue screen that has vertical white lines that move across the screen. Eventually if left on the lines will change colors to multi colored lines and stop moving. Fills the entire screen. Just fyi I did do a voltage test on xp805 on the power board and I'm getting 19v on pin 10 and 9 instead of the 16v the board says. Pin 7 I get 3.3v pin 4 I get 4v, 5 on pin 3. All the other pins were what the board says. These are reading with the tv plugged in and power button on

I would suggest you have a connection problem.
Taking a TV apart that was working fine and then it dies this is what most of us have had.
Suspect is the connections of the ribbons from the t-con. Inspect at close range they go in all the way. That is trickier than you think.
Many times you see the ribbon cable kinked at tge edges. Flatten it gently. Also check the seating of your LCD panel boards. Often they are shorted during assembly. Make sure they float free from any contact. Some have silvery metal tape that connects to the back metal. They ground the boards. Make sure you put these back.

 

[Schepc]

So I double checked the ribbons from tcon to lcd driver and look good. Turned tv back on and get the blue screen with white vertical lines still. I'm reagrds to the lcd boards I'm not sure what you exactly mean about floating freely. The had clear tap on them when I took them off. There is also on each end black like tape that goes from the chassis to the lcd screen.

 

[RinusB]

I would suggest you have a connection problem.
Taking a TV apart that was working fine and then it dies this is what most of us have had.
Suspect is the connections of the ribbons from the t-con. Inspect at close range they go in all the way. That is trickier than you think.
Many times you see the ribbon cable kinked at tge edges. Flatten it gently. Also check the seating of your LCD panel boards. Often they are shorted during assembly. Make sure they float free from any contact. Some have silvery metal tape that connects to the back metal. They ground the boards. Make sure you put these back.

Also, blue screen indicates

 

[RinusB]

So I double checked the ribbons from tcon to lcd driver and look good. Turned tv back on and get the blue screen with white vertical lines still. I'm reagrds to the lcd boards I'm not sure what you exactly mean about floating freely. The had clear tap on them when I took them off. There is also on each end black like tape that goes from the chassis to the lcd screen.

Can you again remove tge backlight connector from the power board and check if you have a picture or whatever there is?

 

[Schepc]

So when I did a flashlight test originally I could just tell the tv lcds were on. I didnt have an actual tv sat box or hdmi connected to see a picture. So I guess it's possible it was this way when the screen went black and then I changed the leds. I just assumed it was still good as it showed the blue screen when I did a flashlight test.

 

[Schepc]

Are you asking me to unplug the led lights and do a flashlight test then?

 

[RinusB]

Are you asking me to unplug the led lights and do a flashlight test then?

Yes, just unplug them from the power supply board. Do the flashlight test. If it is still a bad picture you can plug tge lights back in.
now remove one t-con ribbon and check the screen. If the screen is half only, put that ribbon back in and disconnect the other ribbon. At all times turn power off between connecting and disconnecting.
Let me know.

 

[Schepc]

So picture was faint on flashlight test. Un hooked on ribbon and half screen was white. Other side blue white with some faint vertical bars and then the same thing if I unhook the other ribbon.

 

[RinusB]

Looks to me like the main board is causing the issue.
Removing the t-con shows it is doing its job but it is not getting a good image signal from the main board. Unplug the main board and remove it. Check closely on the back to see if any components are burned.
having said that, inspect LVDS ribbon to see it all contacts are clean. Clean with alcohol.
Was the LVDS cable a flat Ribbon or a cable with connectors? If the cable has connectors and they are the same at both ends, reverse the cable. Then test again.

 

[Schepc]

Looks to me like the main board is causing the issue.
Removing the t-con shows it is doing its job but it is not getting a good image signal from the main board. Unplug the main board and remove it. Check closely on the back to see if any components are burned.
having said that, inspect LVDS ribbon to see it all contacts are clean. Clean with alcohol.
Was the LVDS cable a flat Ribbon or a cable with connectors? If the cable has connectors and they are the same at both ends, reverse the cable. Then test again.

So main board looks good do not see any burn marks. The lvds cable is actual wires and not a ribbon. All the connections do look fine. And I cleaned them. The only thing I see that might possibly be something is on the power board circuit number vd812 it's a black square with a screw to a large black board. The black square says draco sff1506. The metal prongs are sorta goldish color. Other than this it looks good. The only other thing that seems odd is on the cable from the power board to the main board it says two of the connectors should be 16v but I get just over 19volts

 

[RinusB]

There are no bulging capacitors on the power board? Voltages are often higher because a load may drop that a bit.
Can you repeat the model number again please?
Easier not backtracking.
Maybe I can get a service diagram.
Also maybe the main logic board number.

 

[Schepc]

There are no bulging capacitors on the power board? Voltages are often higher because a load may drop that a bit.
Can you repeat the model number again please?
Easier not backtracking.
Maybe I can get a service diagram.
Also maybe the main logic board number.

No that was my first thought too. I don't see any bad capacitors and I did check the continuity on the larger capacitors and they seemed fine. The model number is 50k23dg

 

[RinusB]

I think it is the main board. if the lights are fixed and you see all these lines, see if the menu comes up. If not, the main board video is not working. A new board may solve the problem. you need to decide if the TV is worth it.