Samsung PN50B450B1D showing evenly spaced vertical lines

[rifeman2000]

My TV started showing evenly spaced, vertical lines across the entire width of the display. Just eyeballing it, I would say the lines are about 1 inch apart and 1 pixel wide. They are always in the same place, appear stationary, and appear over the top of the TV menu. They also appear on all inputs. When looked at against a lighter colored background, they alternate between a subtle green and subtle red.

I've referenced a post from "capkid" that point to the logic control board. I've taken a picture of the TV with the back off and a zoomed in picture of what I think is the logic control board. Any help would be awesome! Thanks!

-Chad

[tw2005]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

My TV started showing evenly spaced, vertical lines across the entire width of the display. Just eyeballing it, I would say the lines are about 1 inch apart and 1 pixel wide. They are always in the same place, appear stationary, and appear over the top of the TV menu. They also appear on all inputs. When looked at against a lighter colored background, they alternate between a subtle green and subtle red.

I've referenced a post from "capkid" that point to the logic control board. I've taken a picture of the TV with the back off and a zoomed in picture of what I think is the logic control board. Any help would be awesome! Thanks!

-Chad

I'd be thinking along the same line it sounds like it.

LJ92-01617A

There is a procedure to isolate the main board, jumper the logic ctrl bd test pattern generator, I think the PSU also needs to be jumpered to turn on at plugin.

Was there any mention of that in the other thread? If the lines were still there running just off the Logic board that would confirm that's the issue.

[tw2005]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

something like this, you don't have to remove the main board, just need to disconnect the power and LVDS cables.

[rifeman2000]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

Was there any mention of that in the other thread? If the lines were still there running just off the Logic board that would confirm that's the issue.

tw2005, here is the full post I was referring to (from capkid):

I was helping a guy on YouTube with one of these TVs - he has evenly spaced vertical lines. The guy just about drove me nuts:

Me: Since the lines appear to be evenly spaced, I'd say that you have a logic control board problem. I'd try re-seating the connectors or cleaning the contacts with electronic contact cleaner first. If that doesn't work, I'd replace the logic control board; it's the small board that usually sits somewhere near the center of the panel.

TV Owner: Where is the logic control panel? And the connector

Me: It's the logic control BOARD, not panel. I explained in my previous comment that it's a small board on the back of the plasma panel. You'll see the connectors going to that board. Again, either the connectors need to be cleaned or the board most likely needs to be replaced.

TV Owner: I did research on Google n alot of people having the same problem with this tv. They said it could be the y-main board r plasma panel need to be replaced

Me: What's the model number of the TV?

TV Owner: PN50B450B1D

Me: Ok, I've worked on several similar Samsungs. Other people may have just a few vertical lines on one side of the panel, and that's normally a bad panel. In your case, you have evenly spaced lines, which points to a processing issue. There are more involved tests you can do, but first try bringing up the TV's menu to see if the lines are in front of the menu or behind it. Do the lines move or are they always in the same spots? I highly doubt you have a panel or Y-main problem.

TV Owner: So what problems do you think I'm having if its not a panel r y-main board problem

Me: I'm sorry, but you're obviously not listening to my advice. You cannot diagnose an issue without testing it, and you aren't posting any results of tests I've suggested you perform. Please reread my comments. I'd replace the logic control board if the lines are stationary. Hopefully, you can solve your problem. I need to move on. Here's how to identify parts: watch?v=R1jmj_foId0

I've also attached a picture of the image produced on the screen. The lighter colored lines are more apparent, but if you look closely, you'll see the darker (reddish) lines in between each set of lighter colored lines.

[rifeman2000]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

something like this, you don't have to remove the main board, just need to disconnect the power and LVDS cables.

I'll give this a try! As an aside, about how long does it take the capacitors to discharge so I don't end up frying myself?

[rifeman2000]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

something like this, you don't have to remove the main board, just need to disconnect the power and LVDS cables.

I followed the instructions in the powerpoint. The menus and options on my TV were different then the powerpoint. Attached is what I found.

Control -> PDP Option -> and no way to get to the test pattern.

Going back to Control -> Test Pattern -> I'm able to get either the Master of LOGIC test patterns. The lines appear on both test patterns (I included one from the LOGIC pattern test. The horizontal bars are just distortion from the camera. It actually appears as a solid grey screen with the red and green lines as previously discussed.)

Since lines are present, does the LOGIC test show there is a problem with the logic control board, or is more troubleshooting required; ie, disconnect power and LVDS cables?

Thanks for the help so far! This is a blast!

[martino]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

I'd say logic board BGA chip letting go. Did you try heating the logic board with a hairdryer to see if it chances?

[rifeman2000]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

Going back to Control -> Test Pattern -> I'm able to get either the Master of LOGIC test patterns.

In case it wasn't clear, the section of my message quoted above should read "I'm able to get either the Master OR LOGIC test patterns.

Martino, I'll give what you said a try!

[rifeman2000]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

***FIXED!!*** It was the logic control board...a $15 part! Thanks for all the help.

Is there any way to edit the thread title so that when people are scrolling through they can quickly see what the fix was?

[martino]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

yay! good news and cheap fix

[mmartell]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

***FIXED!!*** Is there any way to edit the thread title so that when people are scrolling through they can quickly see what the fix was?

Nope. There is an old thread requesting this feature but Topper decided against it.

[ReeceyBurger123]

Re: Samsung PN50B450B1D showing evenly spaced vertical lines

Awesome, I have the same Tv im repairing and I have added heatsinks to the Bga chips on the control as they get hot. You might also want to resolder every Igbt on the Xsus which can help prevent future issues.