lets talk Samsung plasma pink bandung issues..

[freakaftr8]

OK so I got in another 58 inch plasma TV today. This ones a PN58C8000. White screen produces pink bands from inadequate power supply I believe. ok seems to be a lot of talk about this issue on other forums and Google searches come up with a lot when you search pink banding issues. I know I can clear this up by adjusting up the vs voltage but why? It's running at its optimal 210 Volts. What's the deal? Seeing this a lot more lately. if you see I have another thread open about the other 58 inches I have but that one the banding was so bad it was dropping out pixels like as in a bad Z sustain but it was not.

Could it be low amperage? Not so much the voltage? As in increasing voltage ups the amperage also.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

OK this TV runs 210 for vs and -200 for vscan. So I noticed the power supply was low and vs was running at 206. Bumped it up to 210 and cleared up mostly. Still a little banding. Had to bump up to 215,and looked great except a few sporadic sparkles in dark areas. So I found that I had to also bump down the vscan from -200 to about -183 to achieve a near perfect picture.

Also I was correct that the panel us the same as the PN58C680,as it uses the same sustain boards but different power supply. Now on to seeing how long it lasts as people complain that after Samsung authorized repair techs crank up vs and after 6 months it's back to doing the same thing...

I would also like to add that the other TV that had the black patches on the screen was the result of what happens when the purple banding or the pink banding issue goes far beyond and adjustment as that one appears unrecoverable with vs up to 218 with just a little mal discharge still.

also both of these TVs seem to have issues when placed in movie mode under screen preferences. quite a bit of mal discharge and the screen on the other TV almost fades away completely in this mode. It seems to be the hardest on the panel for some reason you would think it would be the easiest since its darker but it doesn't look that way. I think this seems to be becoming a more inherit issue with these newer Samsung 3d Plasma TVs

BTW also Vsch needed a small tweak because when I would flip channels I would see a few green and red sparkles as the screen refreshed.

Also VA was low. Supposed to be 55v it was operating at 50v.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

BTW panel time is 11,500 hours.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

Just powered up the set this morning from cold and it still looks perfect. Odd that I had to set vscan lower with the uprated VS.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

Is there any downside to having to run the vscan lower than rated -200vdc,as it's now at -183vdc?,also the VS is pushed up to 215 from 210..

Also had to play around in the white balance to reduce the pinkish whites and ramp down green bias to accommodate.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

Here's what I got now. And what I had before adjusting.

[Shinju]

Re: lets talk Samsung plasma pink bandung issues..

I have heard of guys doing this to Samsung and LG panels to try and get deeper blacks.

Any long term issues? I dont know but I have been told and read here by plasma gurus that its best to have the voltages with in spec as close as possible.

Also it seems like Movie mode taxes the panels almost as much as Dynamic mode, Every older Samsung plasma I have had even at spec voltage has had minor green sparkles in the blacks when cold some go away when warmed up others it seems to just hang out.. Seems to be more Samsung then anything else. My LG 60" plasmas upclose have minumal rainbow sparkles when they are cold, One has 1500 hours the other has over 6500 both do it, the one with 6500 hours is the one I recently fixed the other I bought from someone who hardly used it in working condition.

[Shinju]

Re: lets talk Samsung plasma pink bandung issues..

Adjusting the Cell Light, Brightness and Contrast sometimes gets rid of those Green sparkles too.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

Yea. Seems that earlier LG had this issue. Now the newer Samsung panels suffer.

However I found that a minor adjustment on the Vsch on YSUS clears these sparkles. It seems that these Samsung panels are going out of spec or wearing fast.

[tom66]

Re: lets talk Samsung plasma pink bandung issues..

Panel degradation happens but what you're seeing seems way out there. I would have thought drive circuit failure over anything else, unless the panel is completely worn out, can't see it.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

That's what I thought but both panels ate from the same model one more severe and unrecoverable than the other. Panel is S58FH-YB05

[tom66]

Re: lets talk Samsung plasma pink bandung issues..

I'd stick a scope on the Y and X outputs just to see what's happening.

[Shinju]

Re: lets talk Samsung plasma pink bandung issues..

Woah, tom66 is gold now! Grats man!

[goontron]

Re: lets talk Samsung plasma pink bandung issues..

Woah, tom66 is gold now! Grats man!

right?!? out of nowhere! but your custom title is gone! anyway.... hope you do better than some other mods ive seen....

[tom66]

Re: lets talk Samsung plasma pink bandung issues..

Woah, tom66 is gold now! Grats man!

I will be moderating the electronics forums only (for the time being) will see how it goes...

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

So poking around the internet I have come across a control board update for this issue that is supposed to change the drive dynamics to accommodate panel aging. Thus is a proprietary Samsung [3D58] logic.bin file. Anyone know where I can get my hands on it? Apparently need a to be loaded via service remote but I found the service remote program as long as I can do it over LAN. Tom back in 2013 you had a lot to say about this issue on another forum I noticed so you know about this issue. The banding only seems to affect a certain number of models all using this same panel.

[tom66]

Re: lets talk Samsung plasma pink bandung issues..

See, I'm not really sure you're seeing the same issue.

The pink banding typically manifests after around 2-4 years of typical usage, and it appears when bright, mostly full white images appear. Like this:
https://www.youtube.com/watch?v=28UxYb6_vSQ

This is because under load, the Vs reaching the SUS boards and panel drops (the wires, transistors, panel, buffer ICs all have internal impedances, peak currents are high, so you'll see fairly significant droops under load.)

Generally, setting "CELL LIGHT" down will hide the fault. Adjusting Vs up by around 5V nearly always cures the fault because you're overcoming the energy otherwise lost in the panel.

What you're seeing is plain-as-the-day maldischarge. Something is actually WRONG with how your panel is being driven... unfortunately, it's pretty hard to say exactly what is causing it without seeing the sustain waveforms. Plasma panels require nice initialisation pulses before they emit light - if those go wonky or disappear altogether, the picture will not be very good although you usually will still see -something-, which is a lot like what you have.

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

okay well that makes perfect sense but I found it just really odd how on the newer Samsung Plasma that I have that has the pink banding issue it would appear that if I were to turn down the vs the Banding gets to the point where it blacks out in that area. The other Samsung that I have that has the black blotches on the screen is due to an incurable defect where the vs is cranked to the max and it is just barely good enough to power the panel on a full white screen but I still have the pink banding. Without an oscope I do understand that I can't successfully check the waveforms however being said Samsung had some quote "miracle cure" for this issue resulting in a firmware upgrade to the control board. Although I was able to tune out the pink banding issue on the newer generation plasma that I'm working on now by cannot tune out the issue on the older plasma. I have swapped both XY and control boards to the older panel with resulting in the same issue I cannot achieve a high enough vs voltage to cure that panel so without being able to swap out the power supply since the main board is different I would only assume is that it could possibly be a panel issue as the panel that is the worst out of 2 appears to only have roughly 7,500 hours on it and the other panel has 11,000 hours on it and it is not as bad as the 7500 hour panel. So I'm really thrown for a loop here I have swapped everything besides power supply although the power supply the panel that has some black spots is cranked up to 218 volts on the vs and just enough to drive the panel.

so this is why I was looking to see if I can get my hands on that bin file and find out if it could possibly take care of some of what I'm seeing going on with the 7500 our panel that has the black spots. I mean there is always a chance that it's just plain old a bad panel but it's hard to tell. It just seems odd that when you have the pink banding issue if you were to drive the vs drive voltageta little lower in that area it would turn black just like what I'm seeing on this particular TV.

sorry I'm not trying to confuse anyone its two tvs I have that are in question are A PN58C8000 which is the one that has pink banding on white screens. And the worser of the two is the Pn58C680 that has T black blob dropout under full White condiWhite or even brighter scenes in that case. I'm wondering if anybody with this defect that has cranked up the vs drives has noticed anything and long-term. I can vouch that I have been running the C8000 for 72 hours straight now after adjusting the drive and I have noticed on white screens I have a very minut amount of pink banding again even at 215 volts DC on the vs.

BTW adjusting cell light down on the C680 helps but doesn't cure it

[freakaftr8]

Re: lets talk Samsung plasma pink bandung issues..

problem fixed. Tarnished connections on Z sustain ribbons going into the panel. Watch out for this they started getting pinkish colored like what happens when copper sits in water. I clean them with an eraser and problem solved perfect picture. Never seen this before!

[tom66]

Re: lets talk Samsung plasma pink bandung issues..

Interesting fault - definitely new to me. Both TVs?