Samsung inverse picture

[jurgyman]

I have a Samsung ln40a500 LCD with a mostly white, inverse picture.
I tried a brand new tcon board but it looked the same. What to try next?

[budm]

Re: Samsung inverse picture

Please up load good clear pictures of the screen to show us what you are seeing.

[jurgyman]

Re: Samsung inverse picture

[attainteddragon]

Re: Samsung inverse picture

disconnect one ribbon cable that goes from the t-con to the panel at a time and see if you get a clear picture on the half that is connected. reinsert first cable and disconnect other side and check pic again.

[jurgyman]

Re: Samsung inverse picture

One panel cable disconn, half screen freezes, goes white. Same if other disconnected.

[attainteddragon]

Re: Samsung inverse picture

hmmmmmmm. you could check the vgma test points on the t-con to see if it is a gamma issue.

was your replacement t-con new or used?

is the t-con on the lower side of the panel?

[tom66]

Re: Samsung inverse picture

I would say this is likely a gamma issue.

[chrismurphy]

Re: Samsung inverse picture

my verdict faulty T-con

[Davi.p]

Re: Samsung inverse picture

Surely is tcon faulty, if it has an AUO panel is surely AS15 chip, search for "as15" in the forum, tons of threads, tons of chips on market, ebay, aliexpress.

[jurgyman]

Re: Samsung inverse picture

Had gotten a new replacement same board tcon from ebay. but it looked the same, even whiter and washed out than original. Im sending that one back.

If its a gamma issue, where is that addressed?

[jurgyman]

Re: Samsung inverse picture

I redid the disconnect tcon to panel cables... and got snaps.

[budwich]

Re: Samsung inverse picture

what's history on the set (ie. how did it get to this "state").

[jurgyman]

Re: Samsung inverse picture

TV is a pick from the local electronics recycling site.
so for me its always had the white-washed inversed picture :-)

[Davi.p]

Re: Samsung inverse picture

You have luck! (to find it..) It's not unuseful to buy faulty tcon for working or NEW ones! Watch on the tcon, if there's a chip named like AS15-F, take a photo of it closely, i'm curious if someone has made a bad repair. It's better to buy a chip and go in a cellular repair shop asking it to solder it. Ah, usually with faulty as15 it tends to go whiter after you switched on the tv ..

[jurgyman]

Re: Samsung inverse picture

Is there anyone related to badcaps community that could replace the tcon as19 chip ? willing to pay around $20-25 (about the cost of another tcon board)

[attainteddragon]

Re: Samsung inverse picture

let's confirm the fault first.

on the top of the t-con, there are 18 test points within a white outline and gamma written in the middle.

can you measure each point in numerical order and let us know the result.

[Davi.p]

Re: Samsung inverse picture

I had asked for a close view of the chip, there i can't see the pins well, but anyway..

[jurgyman]

Re: Samsung inverse picture

Here is a closeup of the chip: AS19-H1G
doesnt look modded to me.

[jurgyman]

Re: Samsung inverse picture

Here are the requested tcon test point voltages.
01 15.26
02 12.77
03 11.99
04 11.45
05 11.84
06 10.71
07 10.03
08 9.04
09 8.06
10 6.87
11 6.28
12 5.53
13 5.12
14 4.71
15 4.37
16 3.44
17 2.62

DRL1 3.23
OE1 0.78
STV 0.0
CKV 0.0
VSCM 6.81

in this video, I skipped 12, but then corrected myself. above Vs are correct.
https://vimeo.com/234130462

[microvibe]

Re: Samsung inverse picture

Is test point 4 + 5 switched around if it's not then that's tge problem. higher voltage on test point five than test point 4.