test y buffer for short? part# ebr38447802

[Hemant007]

Re: test y buffer for short? part# ebr38447802

Hi, I am trying to test Y buffer, can you please advise on selecting ground pin, I don't see any labelled as ground. Attached is connector photo on Y buffer board, thank you

[shelby5041]

Re: test y buffer for short? part# ebr38447802

i installed 4 diff y boards and tv had exact same problem so im going to assume the y boards are all good since all 4 cant all have same problem....the thing now is either the panel is bad or the upper buffer was the issue or the z board is bad

[shelby5041]

Re: test y buffer for short? part# ebr38447802

thanks

i am going to repair this tv no matter cost....i dont care about cost anymore im beyond caring i have way too many hours into this tv to walk away now

i appreciate your help....i bought a upper y on ebay that is not shorted and i will try to intstall it without bottom buff connected and also disconnect z and see how tv acts

[tw2005]

Re: test y buffer for short? part# ebr38447802

still not sure whats wrong with tv.....the buffer being bad should have triggered a black display and it didnt so i suspect the tv has other issues

the y buffer upper was shorted yes but then why wouldnt the top half of the display be black???

its not black its very bright pink and white....so im confused

Well if it was shorting out , may have then dragged the Ysus voltages / signals down and hence bad image / maldischarge. I've seen shorted buffers cause a messed up image in a Lg. i think that's where I started on first impression. I would have thought with no top and bottom only you may have an image but not sure if that's true or not. I guess if you had not put so much $ in to it it may be worth going on but they're not a brand I chased for projects, except if virtually free.

I can't help guide you really anymore, we all learn along the way, winners & losers. these just turned out to be unlucky for you.

[shelby5041]

Re: test y buffer for short? part# ebr38447802

still not sure whats wrong with tv.....the buffer being bad should have triggered a black display and it didnt so i suspect the tv has other issues

the y buffer upper was shorted yes but then why wouldnt the top half of the display be black???

its not black its very bright pink and white....so im confused

[tw2005]

Re: test y buffer for short? part# ebr38447802

So it is looking that just the buffers were stopping you fixing this which I was starting to suspect. It would be nice to see these working but at how much more expense or bad luck?

[shelby5041]

Re: test y buffer for short? part# ebr38447802

uh oh.....it came off but all of the pads came off with it........i figured it wouldnt work....worth a try

[shelby5041]

Re: test y buffer for short? part# ebr38447802

oh well cant get the chip off.........heat gun wont melt the leaded solder........

[shelby5041]

Re: test y buffer for short? part# ebr38447802

i want to thank everyone who helped me on this issue

using the various testing methods i have proven that in fact all my upper y boards bought on ebay and shop jimmy are are shorted 100%

after doing the tests i marked the chips that tested shorted and since the boards are no good in my mind i decided to take it one step further...i took the heat sinks off to see what the chips looks like and see my photos.....everyone that tested shorted were broken or burnt or holes.....see brown spots under heat sinks....

so this thread is officially over.....

thank you again..........the tests work.....and pictures say it all.....photos dont lie...as much as the ebay sellers want to say their board is good...its all BS...i have proven them wrong...

[shelby5041]

Re: test y buffer for short? part# ebr38447802

pic is in this post along with part #

u can look it up on ebay or shop jimmy

i cant send another pic now im mobile

[tom66]

Re: test y buffer for short? part# ebr38447802

Please supply a picture of your board showing where you are testing as I am now thoroughly lost.

[shelby5041]

Re: test y buffer for short? part# ebr38447802

im testing the boards for short out of tv..there is no locations that you mentioned on my y buffer board

[tom66]

Re: test y buffer for short? part# ebr38447802

Those ones, there should be one at the top of the board (that's VFG+VSCAN) and two in the middle, which is the floating ground.
There are also sometimes ordinary ground screws - they go into the chassis - don't use them.

[shelby5041]

Re: test y buffer for short? part# ebr38447802

how do i identify a floating ground pin?....the pins just say gnd on the buffer board

i used the large copper pads that the screws mount to....

[shelby5041]

Re: test y buffer for short? part# ebr38447802

and lots of sellers put z and y boards on ebay that are defective and they dont know that........its frustrating trying to troubleshoot tvs when boards you buy to try to fix...dont work.....

[tom66]

Re: test y buffer for short? part# ebr38447802

I use the floating ground pins to the output pins, yes those are the ones connecting to the ribbon connector.

[shelby5041]

Re: test y buffer for short? part# ebr38447802

by out put pins you are referring to the numerous pins on the 4 ribbon cable connectoirs?...if so what do i use for ground?...the gnd pin on the incoming power connector or the floating ground pads where the screw mount the board?

i used the floating ground pads....and gnd on incominmg pwr connector and came up shorted also


i did that.....

[tom66]

Re: test y buffer for short? part# ebr38447802

A lot of newer plasmas will damage the buffer board when the screen gets cracked... sellers stick them on eBay without testing them

No, you need to check to the output pins to be sure

[shelby5041]

Re: test y buffer for short? part# ebr38447802

thanks

ok thats what i thought...bought it on ebay just got it and tested it shorted


have to ask for refund....seems the upper boards are more prone to short on this tv..is that an accurate statement

can i also test for short on buffer board by just probing 5v pin and probing gnd on same incoming power connector and if it beeps....board is shorted?

[tom66]

Re: test y buffer for short? part# ebr38447802

Yes that would be a shorted buffer board