50" Plama vertical lines - repairable??

[Stevie B]

I've been using my Maxent 50" monitor/TV (no tuner) as my computer monitor for about 3 years using an HDMI input.
It's about about 7 years old.
Never had any issues - until yesterday.
I had it on for about 30 minutes (working fine), and it suddenly displayed with multicolored vertical lines across the entire screen, top to bottom.
I heard no noise when it occurred.
Same problem exists on all inputs and menu function display.
The lines are stationary but seem to vary depending on what image is being displayed.
They are sometimes 2 or 3 or up to 5? pixels wide.
There appears to be other colored artifacts around certain displays.
There are no other types of lines.

The TV has some kind of input selection thing that when no signal is detected it displays solid blue. This still shows up with a solid blue without those lines.
So I'm thinking it's not the panel???

Has anyone had experience with this specific issue?

I'll try and attached a couple of pictures.
(The horizontal black bars are from the camera phone synch, not visible in real life)

I've never dealt with TV repair - only tube amplifiers - but now I'm very interested in learning about this stuff

Any help is appreciated.

[tom66]

Re: 50" Plama vertical lines - repairable??

Not panel, looks like digital board. Who made the panel in the TV? Pictures of boards and chassis would help.

[Alastair E]

Re: 50" Plama vertical lines - repairable??

Very much doubt its the panel--in fact I would go as far as to say,--No way is it that.

Possible Control-Board, but I'm thinking more the mainboard....

Ah--Tube (Valve) Amplifiers--another passion of mine, designed and built quite a few,--Forget everything Valve related when working on Plasma sets--Nothing seems to apply from the dark-arts of Valve technology!

[Stevie B]

Re: 50" Plama vertical lines - repairable??

I believe it is a Maxent MX-5020HPM.
I haven't opened it yet to see if there are manufacturer's labels, so I don't know who made the panel itself.
Here is a close up of the lines...

[Shinju]

Re: 50" Plama vertical lines - repairable??

You will need to open the panel before anymore troubleshooting can happen. I think Maxent had both Samsung and LG versions if I remember.

Before buying any parts try cleaning and reseating all of you ribbon cables from your logic/controller board. Once you get some photos of the guts someone can direct you on what you need to do next and what boards you are looking at.

[Stevie B]

Re: 50" Plama vertical lines - repairable??

After I open it up I'll post pictures of the boards and layout.
Could it be as simple as the ribbon connectors needing a mechanical refresh?

I wouldn't call vacuum tube amps "dark-arts"; more like "classic" audio design
(admittedly much simpler to understand)

[Stevie B]

Re: 50" Plama vertical lines - repairable??

Thank you all for such great responses.
Great forum. Great site.
(Those bad caps infiltrated lots of Fender amps starting about 8 years ago too.)

I'll try to open it tonight, it's about 100 lbs and it's still up on the wall (I'll need help).
More pics and posts will happen then.

[Shinju]

Re: 50" Plama vertical lines - repairable??

Tom66 has a plasma troubleshooting guide. I would recommend searching for it and do a little reading and see what you are going to be diving into. When you crack that sucker open you are going to be like WOAH!

These older plasma's have a lot going on inside of them.

[Stevie B]

Re: 50" Plama vertical lines - repairable??

OK, I'm back after a frenetic "end of year".
I have cycled all the physical connections (ribbons/connectors) I could access without board removals, and the set is still with the "noise" symptoms.
It exists on all inputs.
No real change after the "refresh" but now it seems to have more "movement" - as I recall, the "noise" seemed more stationary before. (could be my memory though)
Visual inspection of the installed boards shows nothing that I could see.
I pressed several locations on boards and components while viewing the picture's reflection and there was no change.
I have several photos to post.

[Stevie B]

Re: 50" Plama vertical lines - repairable??

There is a definite pattern in one section of the screen that does not extend all the way to the left

[Stevie B]

Re: 50" Plama vertical lines - repairable??

But that pattern temporarily shows up on the right side at start up too...

[Stevie B]

Re: 50" Plama vertical lines - repairable??

With an input, the picture has the "noise" across the screen but also has that additional peculiar pattern on the right - and stays there on the right.
(I just realized I have my left and right backwards n the previous posts)

[Stevie B]

Re: 50" Plama vertical lines - repairable??

Power supply looks fine...

[Stevie B]

Re: 50" Plama vertical lines - repairable??

Main board looks fine...

[Stevie B]

Re: 50" Plama vertical lines - repairable??

Left and right sus boards look fine

[Stevie B]

Re: 50" Plama vertical lines - repairable??

Top and bottom look good

[Stevie B]

Re: 50" Plama vertical lines - repairable??

bottom left

[Stevie B]

Re: 50" Plama vertical lines - repairable??

There's a small board behind the main board that I didn't get to see without disassembly

[Stevie B]

Re: 50" Plama vertical lines - repairable??

I'm looking for someone who can suggest which boards to replace - or let me know that it may be cheaper to buy a new 50".

[mmartell]

Re: 50" Plama vertical lines - repairable??

The last board you uncovered is the digital board and the one tom66 is referring to. I would heed his advice and replace it. I had a similar "interference" problem in a Pioneer plasma which he suggested I replace and it was the problem.

Who makes this tv ? You need to get the part number from the control board.