Weird issue with this tv. Was streaming to the from a computer when it stopped working and the screen went black. Ever since then there has been. o image. Just a black screen. The audio works and yhe backlights do come on when it's powered on, it's just a black image. It presented like a backlight issue. So I finally got around to getting new backlights and a backlight tester. All of them test the same as the good backlights with the same voltages. There are no blinking lights. Just the white led at startup and when buttons on the remote are pressed signaling it's receiving from the remote. Soft. hard. and factory reset haven't changed anything. Ive unplugged the lvds cable left, right, and both and none produces an image on the screen nor a fault. If I disconnect the ribbon cable from the led driver to the main board I can get it to 4 blink fault but it goes away as soon as it's reconnected. Does this sound like a bad panel if nothing will display except backlights?
-
-
Test the screen. Generally you can jump the TCON without main board connection.
Take a picture of the whole back of the TV with all boards and then a picture of PSU/TCON and Main/led drivers. And can probably better direct you -
Comment
-
I can't see the legend on the power board BUT. Disconnect the connector clip from the PSU to the main board. Then disconnect the clips from the Main board to the TCON at the TCON.
Then you need to jumper, TCON on, PS on, STBY and BLON.
Then plug it in. Potentially a color pattern of RGB will come on the screen. If it does and no distortion on the screen that's a good sign. If it doesn't, use multimeter and see if tcon is getting the voltage necessary by checking voltage at the fuseComment
-
Ok tried the jumper thing. The power supply clicked but nothing close to turning on or image on screen. no backlights either. So then I remembered I had another power supply from the same tv that should have no issues as it was pulled from a cracked screen. Put that in and it wouldn't even power on. Switched back to the original board and same thing. no power. Not sure if that jumper tripped something. Even though it wont power on I still get the power on and standby at 3.34v but nothing to tcon. But without it on I can't really get a reading of what it should be.Comment
-
I know I've tried this before and it didn't work either. It's not likely the PSU at all so.. yes. If you had a cracked screen PSU then you don't have the other boards for it?
Plug everything back in normal and see if there is 12v at the TCON fuse on both sides.
When the TV is on also, everything plugged in, you say you get backlights. What voltage does tcon on and tcon 12v (or 20/24) read?Comment
-
I sold the other boards before I ever got this tv. Only has the power supply and wifi board left. Unfortunately I can't check anything as it won't turn on with either board now. Not sure if the jumper somehow shorted the main board (because i do t get the red light on optical and wont power on anymore) but I thought it was completely disconnected before I reconnected the power cable to the main board. Might have to try to get a whole set of boards if I can find them cheap enoughComment
-
Here is the power supply legend. Even though I can't power on the tv now, I get 3.37v on power on and 3.45v on stby. All 12v line in the middle are 12.7v. Tcon_on is 0.0 and all.of the tcon 12v lines show -0.004v.Comment
-
BEST practice is to use about 1k ohm resistors for jumping for safety so nothing effs up during jumping. Testing should be done in order according to fault, if you can't get the tv to do what it did before jumping then you probably did mess something up on powerboard.Comment
-
So what is different after jumping, ie with everything hooked up normally? did you say you had the red light at optical before jumping?Comment
-
A simple firmware update has been known to fix this issue but who knows what is messed up now, like I said, things need to be done in order and tests need to be done correctly.Comment
-
After jumping, nothing turns on. No lights, nothing. Before it would turn on and you could get audio and and have the red optical light and the backlights would be lit. After it's totally dead. No signs of life. Seeing as I have the 12v on the powerboard as well and standby and power on voltages, I'm guessing something happened to the main board when hooking things back up.Comment
-
Ok, this info. needs to be relayed early, it saves going down roads already driven and lets everyone get to solution much faster. Do you have the red optic light back on the mainboard?Comment
-
I need quicker responses, my ads won't allow me to stay on one subject without input.
Comment
-
I did list that before. Before I did the jumper yes. And the tv turned on. After the jumper, no. And it doesn't turn on either. But I have the 12v and 3.3/3.4 standby and power on voltage on both power supplies. My guess is the main board was affected after hooking things back up after the jumper somehow. It was working fine. Now it's totally dead. I'm likely going to have tonofmrder a new main board before I'll be able to do much else.Comment
-
So I'm not mistaken, I shouldn't any voltages on the tcon pins of the power board until the tv is turned on correct? They are all zero or one is -.0004Comment
-
I decided to test if the power supply was bad, which I doubted it was. I unplugged power to tcon and main board and then jumped tcon on to standby and power on and got proper 12.7v on the tcon 12v lines. Main board is what's keeping it from powering on now. Somehow I managed to kill it after the jumper yesterday. I guess I need a new main and going back to the original issue maybe a tcon board as well. Are there any good ways to determine if the tcon is good without a working main board?Comment
-
This is what I said to do. Jumper ps on, TCON on and stby. With main board disconnected. The 12v is what we needed. This was trying to get to the fact that the main board was effectively bad. Which is what I learned towards in the very beginning. Not sure how this wasn't communicated properlyComment
-
Maybe youre getting terms mixed up, nowhere does it say you did a firmware update.Comment
-
I'm stuck on this tv. It has sound, and has backlight glow, but no picture. I've tried new power board, and new main board, but no change. Tried a new t con but still no change. I've updated the firmware after new parts with no change. Is it likely the panel is just dead of would it be lvds cables. I did take some shorter ones I had on hand and connected those between the main and t con just to see if I'd get a picture but no luck. I'm not sure what else there is to blame. Do screens just go out completely but remain with a backlight glow? The screen has been removed and used a backlight... -
Hello everybody! Posting this in hopes somebody has some expertise that leads to a clear path of troubleshooting that saves me a lot of time!
My macbook has the flex cable problem, the one that prevents the screen turning on. Ive been dealing with this for the last 3 years. Last year it went dead and I managed to fix it following youtube tutorials. But my fix wasnt the best, the problem returned a month later. This week, it went dead again. I again tried to fix it.
This time the original cable broke too close to the screen, it can't be fixed without tearing the screen... -
Hi guys
I'm trying to fix this laptop screen
Basically the owner is a computer shop and they brought it to me with two screens. They said the repair shop they use could not fix it, so I thought i would try to see if I am better than their current repairer!
OK so I have the original screen which works but has lines across the bottom quarter of the screen
I have the replacement screen, which they fitted and it worked. They then put the laptop on one side for a couple of weeks until they found a buyer. When they showed it to the buyer, the screen would... -
Hi all, I’ve got a problem I hope someone can help me fixi.
I have a Panasonic TX-48CX350B tv , it powers up ok but the screen is blank, the backlights are working, there’s nothing else though, no picture or sound. I’m not sure what the fault is called whether it’s BLANK/ BLACK/ or WHITE SCREEN I’ve actually came across this before on a similar tv but just ended up scrapping it, I will upload pictures of the boards etc , if anyone could help me I would really appreciate it...01-11-2025, 03:18 PM -
Just had a customer bring in a M2 MBA A2681 that had had a screen replacement in April at another repairer. Since then, she has been getting intermittent kernel panics. It's an aftermarket screen, and of course it fails in diagnostics as the calibration hasn't been done. The error in the panic log is "No device added after powering on the rails".
It seems the original repairer has swapped the board and the screen to other MAC's, and said that it isn't a screen issue. From what I understand, by doing a quick search on Google, this is in fact a screen issue. The panic relates...07-31-2025, 08:37 PM
Comment