50" Samsung pn50a510p3fxza Plasma - Red Screen

[freakaftr8]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

It looks like a bad upper buffer to me. Hopefully you can return it or exchange it anyway.

[freakaftr8]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

Curious does the screen look similar with just the lower buffer connected? Of course it's not going display an image though but I'm looking for the various volumes of maldisarge to see if the y board looks like it's working properly

[ttraband]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

Sorry to be late getting back to you. Stepped away from this project for a few days.

With the upper buffer removed completely from the tv, the bottom half of the screen still shows red snow, but with a blacker background, if that makes any sense. I'll try to upload a picture to go along.

[freakaftr8]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

OK so before you mentioned you're VS and V scan was falling. Apparently it's holding consistent now? And with the upper buffer board connected is it holding consistent still? Something doesn't seem right with the sparkles that you're getting on the lower. Sometimes you will get a maldischarged image without having the upper connected also, But this looks rather erratic. Have you done in ohms test on the upper board to see if any pins are shorting to ground? Also I would perform the ohm test on the lower board just to be sure.

[ttraband]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

I don't know what caused the change, but Vs and Vscan are now steady. I'll see about ohms testing the buffer boards in the next couple of days and post my results.

I'm considering looking at eBay for another set of buffer boards, but I'm concerned that if there's an issue with the Y sustain, that may just damage the new (to me) buffers. Is there a way to evaluate the health of the Y sustain?

[freakaftr8]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

It's hard to tell but if you're getting good Vscan and your VY ramps look good if you have access to a scope then there's not much more you can really do, Replace buffer boards and cross fingers.

[DXseekerMO]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

I got one of these exact same models with a direct short on the y-sus board. You have the right guy helping here....how are you freakaftr8?

[nomoresonys]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

https://www.ebay.com/itm/Samsung-PN5...EAAOSwALtaZlAB
one upper Y-buffer board 7.50 free shipping, says 100 percent working from used tv.

[freakaftr8]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

Just noticed something after looking at your last posted picture. The line that is black is showing up right at the top of the lower buffer board connected still. You say you have a couple different lower buffer boards. Is that line show up when you swap buffer boards in run just a lower with the other board too? It's so that is a bad panel but should not cause the red maldischarge that we're seeing.

Doing well DXseekerMO!

[ttraband]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

Just put in another pair of buffers (off eBay) and still have the same red screen. I'm starting to believe its not (or not just) the buffers. This latest set gives me 2 (or maybe 3) black horizontal lines, one about mid-screen and 1 bolder (or 2 adjacent) lower down.

Seems like the upper connector on the y-sustain itself may be shorted. I've got continuity between all the upper connectors I can test from the front of the board until the lowest 3 pins.

Any suggestions of components or points on the y-sustain to try to troubleshoot, or with the horizontal lines should I just call it quits?

[freakaftr8]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

That's what I feared. Those horizontal lines are caused by a bad panel itself. There is an inherent defect within Samsung PDP panels, Where the ribbon cable connection Somehow disconnects itself from the corresponding horizontal driving line inside the panel. Although this most likely is not the problem with the red sparkles on the screen, You would really need an Oscope to check the VY ramp patterns. Could you look for the testpoints for set_up and set_dn and also -VY? Check these with a DMM first and see if there's voltage there.

Of course this is if you wanna go forward with this TV considering the panel is bad with the horizontal lines anyway

[ttraband]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

Which board would those test points be on? I'm not finding anything with those labels. There are points next to the various connectors feeding in to the y sustain - I've attach photos of the y sustain board. The overall can't be blown up enough to read the silkscreen, so I've outlined where the detail shots came from.


I've kind of got the bit between my teeth now in wanting to ID the root cause.

Thanks for sticking with me through this.

[freakaftr8]

Re: 50" Samsung pn50a510p3fxza Plasma - Red Screen

You say got a few more lines showing horizontally on these new buffer boards then your old buffer boards? How many lines show up on the screen if you re install your old original buffer boards? And does a horizontal line on the bottom of the screen near the middle still show up with either the new buffer boards or the old buffered boards attached?

The reason I'm asking is because sometimes the new buffer boards if they have a shorted IC, Cause horizontal line issues plus red snow.

As to your answer about where the test points are located, I am not seeing them on this y sustain board. But if I were to guess it would be located near the bottom of the board where the potentiometer is located between the two aluminum heat syncs.