this ones throwing me for a loop. The guy picked it up from said all the screen became a little dark in areas And it had a lot of pixelation so I had to go check it out. Ended up picking it up and I brought it home what happens is that it has a lot of black areas in a lot of pixelation kind of Like a bad zsus. all voltages check with its Spec including Vscan. oddly the panel has a label for ve but I cannot find ve on the Z sustain board. so far there watching this TV and I noticed that after a little bit of time the picture starts to clear up the black blotches start to disappear however they don't completely go away. On a full white screen with lettering I see a lot of horizontal purple banding and flickering. Now I have done some research on the internet and noticed that these c-series and b-series 58 inch plasmas from 2010 are known for having bad panels? Well I went ahead and cranked up VS from its original 210 to maximum that the power supply can output about 218. Pictures almost perfect a little black dIthering and some green and red mal discharge . I was able to take care of by turning vscan from its original - 200 -203. so all is well now except for the fact that I'm a little concerned about the higher vs. Voltage but as soon as I went into the menu and started playing around with the picture modes of course it was set in dynamic if I go to movie mode the screen completely starts losing its picture almost as if I unplugged the z sustain. but if its in standard or dynamic the picture seems decent it's still not perfect but a lot better. Now if I put it in 3d its all messed up a lot of green dithering lot of green mal discharge sparkles and some green vertical lines all through the screen. So does this sound like a panel ? Losing it is possibly? I noticed Y & Z sustain boards are relatively cheap for this TV however I have not pulled the boards to find out if there's any bad components but since they're working I would only assume that they're doing their job including especially since all voltages seem to be present and accounted for. I have not heard of Samsung's having bad panels like this have you?
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Samsung PN58C680 black blobs
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Re: Samsung PN58C680 black blobs
Looks like an X-main (Z-sus) failure; a lot of panels will work nearly good enough with a missing Ve-bias period, which I think is what you are seeing.
Note, some Samsung panels use Vb instead of Ve. Same voltage.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: Samsung PN58C680 black blobs
@freak if you've got a scope going spare you can check X-main output and see if it's bad or if the panel is bad (I think 99% x-main here... I can't really see a panel do this if bad.)Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: Samsung PN58C680 black blobs
okay I'm going to get my scope back from my father in law he's had a long enough lol. Yeah ill scope out the x-main and see if I can find a problem there but maybe before I do that I'll just go ahead and order. it's only $20. I feel a little uncomfortable running the vs 8v higher than normal and vscan about 4 volts overDid I leave the soldering iron on?
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Re: Samsung PN58C680 black blobs
I've been searching the internet and finding a lot of threads about these newer Samsung panels going bad in samsung replacing them because of this purple banding issue on a white screen. It seems to me that the purple Bandung people are getting away with adjusting the vs voltage up but now however the screen appear to be getting to the point where they cannot adjust it up anymore. If you had to push vs voltage higher. it looks like an even factory authorised repair centers were going out in changing these voltages to clear the purple banding issue. I mean obviously on a white screen you're pulling maximum voltage and maximum wattage through the power supply. is there a possibility that the plasma panels are losing their charge?Did I leave the soldering iron on?
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Re: Samsung PN58C680 black blobs
No...
What's happening is as the panel ages, the driver board is failing to compensate for panel changes. Increasing the Vs hides this (and should fix it, as the panels "settle in" to a point.) Samsung set the Vs low to start with to save energy.
The reason you get pink tints on bright images is because the electrode resistance drops the sustain voltage on each cell below the threshold for the blue cells to discharge fully.
Plasma panels don't need regassing and they should last much longer than 6,500 hours... Only if they actually are really worn out (like 50,000+ hours) do they start giving real issues.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: Samsung PN58C680 black blobs
kind of like that pioneer that I had a while ago remember that one? They had somewhere around the lines of 73,000 hours on itand it had a black blob in the center of the screen that never cleared up as soon as I cranked the vs voltage way up the screen. Watchable again
[/B]Originally posted by tom66 View PostNo...
What's happening is as the panel ages, the driver board is failing to compensate for panel changes. Increasing the Vs hides this (and should fix it, as the panels "settle in" to a point.) Samsung set the Vs low to start with to save energy.
The reason you get pink tints on bright images is because the electrode resistance drops the sustain voltage on each cell below the threshold for the blue cells to discharge fully.
Plasma panels don't need regassing and they should last much longer than 6,500 hours... Only if they actually are really worn out (like 50,000+ hours) do they start giving real issues.Did I leave the soldering iron on?
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Re: Samsung PN58C680 black blobs
Originally posted by freakaftr8 View Postokay that makes sense so basically with my VS voltage maxed out the potentiometer will not turn any more I'm at 218 volts so the power supply is under compensated for the task at hand?Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: Samsung PN58C680 black blobs
Also if you look at these Y and Z boards unfortunately I didn't take any pictures right now I'm at work.
They are set up in such a way that they can be mashed into a flat chassis meaning there are no heatsinks standing out everything is horizontally placed like today's TVs are superflat. However the wall mount pegs stick out the standard amount and so does the power supply. It looks like this was around the era where they were converting to the super flat chassis so the boards were already set up this way.Did I leave the soldering iron on?
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Re: Samsung PN58C680 black blobs
The LG I just fixed had severe pinks in the whites when the Xmain was going out. After I replaced the board it was fine, whites look white ect.
Heh, I don't know about you two but now that I have been doing more plasma then LCD but I swear every little pixel noise I see I think OMG somethings wrong! Especially on the big screen plasma because of being up to close.
I have to admit its been a lot of fun playing with Plasma over LED/LCD!
Heh sorry to thread jack!
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Re: Samsung PN58C680 black blobs
You want thin plasmas? See Panasonic's TC-P54Z1...
http://rapidtvparts.com/image/cache/...-1200x1200.jpg
http://www.zdnet.com/i/story/61/18/0...file-angle.jpg
I think the boards are remnant of the Samsung PN58B860 which was also an ultra slim chassis.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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