samsung 50 inch plasma

[tom66]

Re: samsung 50 inch plasma

So just a slight glow from the bottom? I suspect you have a bad Y-buffer upper and Y-main. These are repairable and documented, but it's reasonably involved and you'll need a good soldering iron and preferably a hot air gun.

[adamp91gvm]

Re: samsung 50 inch plasma

I have spare chips it's the second one down by the looks of it

[tom66]

Re: samsung 50 inch plasma

The second on top? You have to repair Y-main too, or the buffer will fail pretty quickly again.

[adamp91gvm]

Re: samsung 50 inch plasma

Yer second down from the top on the top board yer I will do have to have a look how to remove the chip

[adamp91gvm]

Re: samsung 50 inch plasma

What's the paste called that's used to re join the chip to the points I have seen a few videos on you tube and he heats it up and it solders the connections

[Alastair E]

Re: samsung 50 inch plasma

Err--Solder-paste!

Doh--dont you just hate it when some smart-ass does that!

[adamp91gvm]

Re: samsung 50 inch plasma

Ha ha did not know if it had a special name like everything else

[tom66]

Re: samsung 50 inch plasma

I wouldn't use solder paste except for the bottom pad - it's too messy to rework a board with solder paste.

[adamp91gvm]

Re: samsung 50 inch plasma

It looks very hard to solder each one of them points for that chip there very small

[adamp91gvm]

Re: samsung 50 inch plasma

https://www.youtube.com/watch?v=ZypX...e_gdata_player

[tom66]

Re: samsung 50 inch plasma

It's one method. It's OK for low pin density like that. But it is a lot more difficult when the pins are so closely spaced. You get too many bridges, sometimes between pins almost impossible to take off.

It's not that hard, but practice on a scrapped board first.

The preferred method is known as drag soldering. Tack each corner with solder while holding the chip in, then drag the solder over each pin. Wick away any excess (the excess will be on top, so you can wick it easier - with paste, the excess gets between pins, or worse, underneath the chip, nearly impossible to remove.) If you get the speed right and use the right amount of flux, you won't even need to wick away the solder. It'll come away perfect.

See here:
http://www.youtube.com/watch?v=5uiroWBkdFY

He uses a bit of paste on corners and solders it, along with kapton tape to hold the chip in place - it's a personal preference, you can also just tack pins manually with solder if you don't have any paste.

If you do buy paste, be aware that the yellow stuff on ebay is essentially useless. You want the grey stuff. Flux can be in liquid form or paste form, either works.