Samsung LE32A430T white, hazy picture (replaced AS15F)

[Dannyx]

Good day folks. Hopefully someone can point me in the right direction with this Samsung TV which displays a white picture even after replacing the AS15F on the T-con board. I checked the caps on the T-con board and they seem OK. Someone told me it could be a panel fault...has anyone else had this issue when the picture's still the same even after replacing the gamma IC ? Any point in taking off the metal frame and inspecting the buffers ?

[diif]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

I take it you've removed the possibility of it being a faulty AS15 by measuring the gamma voltages ?

[Dannyx]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

To be fair I haven't measured those. I just assumed that replacing it with a new part would immediately eliminate the possibility of that part being faulty. You may be right to a degree, though I doubt the new part is also faulty out of the box...

[Dannyx]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

This is what the picture looks like. As you can see, the OSD is affected as well.

[dick_barton]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

Have you tried the Tcon self test as on page 30 of the pdf attached.

Edit
I must admit that I have not but it has been mentioned on the forum in the past.

[Dannyx]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

Have you tried the Tcon self test as on page 30 of the pdf attached.

Edit
I must admit that I have not but it has been mentioned on the forum in the past.

No, I have not done that because I didn't know about it, plus the T-con in that brochure doesn't match the one I've got and I'm not sure how well the results can be replicated on a different T-con without letting the magic smoke out...will definitely keep that in mind in the future.

[Davi.p]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

Surely there is a gamma correction /as15 problem, are you sure the ic was new? Or you picked one faulty previously removed? Or it is a soldering problem, check it well... if you are in doubt post pictures of the job, how many as15 you have replaced?

[CapLeaker]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

First things first: Measure the Gamma Voltages!

[Dannyx]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

I too believe it's still a gamma issue. The IC was bought new - I never save any SMD parts off of old boards anyway and I never use salvaged parts for clients because they may fail shortly after. I've already closed the set back up, but the solder job looks perfect to me - almost factory made. I wouldn't call myself a pro, however, I have replaced several of these with positive results. Perhaps something killed it immediately after startup :|

[Davi.p]

Re: Samsung LE32A430T white, hazy picture (replaced AS15F)

AS15 is powered from AVDD signal that is 16v approx., check theese vcc pins..