Samsung Plasma PN50A650TIFXZA

[tom66]

Re: Samsung Plasma PN50A650TIFXZA

OK, I think the fault has been located.
Can you get a hold of a hair dryer and start heating up portions of the Y-main board when it is cold, and see if you can make the fault occur quicker?

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

Tom, should I disconnect both buffer boards at same time and re check VSC to see if VSC voltage stays steady.and not a buffer taking out my y main. can you run tv with out both buffer boards in? I Will use dryer on y main. Your post did not show on my thread till I posted this question? It showed that you were last to post, but no post showed up till now. Thanks I'll Heat board up to see if I can get fault to happen right away. Are we looking for cold solder joint?

[vinceroger69]

Re: Samsung Plasma PN50A650TIFXZA

cold solder joint or a capacitor with bad esr too.

[tom66]

Re: Samsung Plasma PN50A650TIFXZA

I would not expect a buffer board to cause this fault personally.

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

Tom, I heated the y main as you suggested with a hair dryer for a few min, turned on set, fault was immediate. VSC measured -113v. Should I replace y main board? Thanks for all your help everybody, much appreciated. George

[tom66]

Re: Samsung Plasma PN50A650TIFXZA

Yes I would suggest replacing the board would fix the problem, however if you are willing to do some tests a repair may be possible which will save you some $.

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

Tom, that sounds great. I'm willing to give it a try along with your guidance. Thank you to all who helped diagnosed my problem.Tom keep in mind I jacked the LG 50PG20 by playing too much. I don't have a scope, only good soldering station and Fluke meter. I do have pretty good soldering skills. I'm a electrical contractor by trade, eye's are starting to go, turning 50 in jan.If you think I have what it takes, lets do this!

[tom66]

Re: Samsung Plasma PN50A650TIFXZA

OK, let's first see if you can try narrowing down the fault. Start heating the area around the yellow transformer on the Y-main, and see if the fault occurs quicker. To make it easier, you can have the TV on while you do this.

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

OK, let's first see if you can try narrowing down the fault. Start heating the area around the yellow transformer on the Y-main, and see if the fault occurs quicker. To make it easier, you can have the TV on while you do this.

ok ,I'll start there.

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

OK, let's first see if you can try narrowing down the fault. Start heating the area around the yellow transformer on the Y-main, and see if the fault occurs quicker. To make it easier, you can have the TV on while you do this.

Tom,I turned set on from cold start.Applied heat on low directly on top of yellow transformer, It only took 3-4 seconds and picture went completely black with sound. removed heat and picture came back in about 2-3 minutes. results in fault almost immediately when heat is applied to transformer.

[tom66]

Re: Samsung Plasma PN50A650TIFXZA

My error, the transformer on your board is green, but I think you have located it anyway, just above VSCAN adjustment.

Can you supply a closer picture of that area.

[martino]

Re: Samsung Plasma PN50A650TIFXZA

Till Tom66 comes back,maybe you can try and narrow the area thats heat sensitive down.
If you can funnel the hot air from the hairdryer through let's say a rolled up paper or something,you can concentrate on smaller areas...
You can do this with TV plugged in and running,just be careful not to touch anything with your hands or dryer..pretty high voltage on Y board.
get tv running,start in one corner of Yboard and systematically heat up areas of the board till you see a reaction,should be fairly instant.That way you can zero in on the problem area or even the problem component...
Maybe then snap a picture of that area?
50 yrs is young,for sure you can do it

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

I'll try to make a cone for my wife's hairdryer. I did place directly on transformer. reaction was almost instantly. I'll try some more closeup pic's They are not working for me here on the forum, using manage attachments, I get constant error message ( site not found) thanks for the suggestion. George

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

Tom, close up pics are on rccrasher65.imgur.com I just added them to the existing album, let me know if you can see them, still not sure on how to use that sight correctly. should be 24 in all. I'm going to make a funnel for hair dryer to pinpoint specific component, wiil try that in a few. Seems that any heat directed to that transformer gives same results as post #30

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

New pics are at www.rccrasher.imgur.com. please let me know if they are not viewable. I think I have made a cone where i can generate heat on specific components, will try to isolate problem component, I have not removed the board yet to look on back with a magnifying glass for cold solder joints. Thanks Martino for that idea.

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

New pics are at www.rccrasher.imgur.com. please let me know if they are not viewable. I think I have made a cone where i can generate heat on specific components, will try to isolate problem component, I have not removed the board yet to look on back with a magnifying glass for cold solder joints. Thanks Martino for that idea.

If you can't view pics try http://imgur.com/gallery/PNIMB/new Thanks guys for your patience. Ill figure these pics out sooner than later.

[martino]

Re: Samsung Plasma PN50A650TIFXZA

pics work wonderful

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

Today I heated other area's of the y main board with no immediate reaction.I got an immediate reaction in area of transformer, like in post 30, also near YFR adjustment. picture started to blink off and on, off and on, pretty much all I can get from heating board. I only have about 10 min to do all this before picture starts to go bad normally. Hope this narrows it down a bit.

[martino]

Re: Samsung Plasma PN50A650TIFXZA

Did you check the solder side of the board around the transformer for cracked solder joints?

[rccrasher65]

Re: Samsung Plasma PN50A650TIFXZA

Martino, I'm going to pull board tonight and check for cold solder joints with a magnifying glass. Report what I find. Thanks, George