Samsung Plasma

[noelgrund19]

Hello all I recently acquired a plasma tv from a buddy model # PN42B450B1DXZC. Condition of the tv is it powers up the audio comes on but the screen has random colors but no image is viewable. I have pulled the back cover off to inspect the caps not showing any signs of failure. Just looking for some guidance on where to begin. Will upload images. Thanks in advance Leon

[tom66]

Re: Samsung Plasma

Have you got a whole shot of the screen we can see?

It looks like buffer or Y-main fault... have you checked voltages, like Vs, Va, Vsc...?

[ammarben]

Re: Samsung Plasma

you have to check all voltages according to your tv

[noelgrund19]

Re: Samsung Plasma

The screen shot image is the complete screen with the top right side showing black(viewing for front). I was just going to get a voltage meter and measure the voltages based on info that I have found here and the specs on the back of the t.v.

[tom66]

Re: Samsung Plasma

That image looks the wrong size to be an image of the whole screen

[noelgrund19]

Re: Samsung Plasma

Okay I'm back got a voltage meter and got some numbers from the test points.
VA 54.2
VS 206.6
VSE - 190.6
VE 90.5
VSCH= - 35.9
TV stamp says va= 54 vsc= -190 vs= 207
There was no numbers for ve or vsch. There was also an adjustable pot for vr-fr but could not locate an measuring point marked on the board.

Just wondering what the next step is know I will continue to read in forum but any pointers will be much appreciated. Thanks Leon

[noelgrund19]

Re: Samsung Plasma

Typo on previous post should be VSC -190.6 sorry about that Leon

[tom66]

Re: Samsung Plasma

Most likely it is a Y-buffer issue, do you have access to an oscilloscope? This can be used to check if the Y-main is working properly.

[noelgrund19]

Re: Samsung Plasma

No I do not have access.

[tom66]

Re: Samsung Plasma

OK in which case you will have to try swapping the Y-buffer, if that does not fix the issue it will probably be a Y-main fault.

[noelgrund19]

Re: Samsung Plasma

Where do you folks recommend looking I look on the net but most everything seems to be out of stock maybe the tv will just be for salvage.

[Shinju]

Re: Samsung Plasma

Posting the part number of the Y Buffer would help

[noelgrund19]

Re: Samsung Plasma

I guess this info would be helpful seeing there are so many different ones out there. The Y buffer model number is 42u1p 2 layer, PCB number is LJ41-06109A. The y main is 42U1P 1 layer and the PCB number is LJ41-05779A. Thanks for any info / leads to finding some parts thanks.

[Shinju]

Re: Samsung Plasma

http://www.ebay.com/itm/BN96-09752A-...item1a00c298d8