Samsung LA37B530P7F LED TV - Whitewash

[TheXFool]

Hi Members,

I was wondering if anyone could offer some guidance in regards to whitewashing that is occurring on my TV.

Attached are pictures of the display as it normally occurs, over exposed with white. If i disconnect the left board from the T-Con board then the image on the right hand side appears normal, but whenever the left board is connected it is washed out. Earthing the pads or moving the left board, or T-con board make no differences on the picture.

My initial guess was to just replace the T-Con board as its relatively cheap and easy to do that, but i thought I would ask first to see if I am missing something.

Please don't hesitate to ask if you require any further information.

Thanks for you help.

[vinceroger69]

Re: Samsung LA37B530P7F LED TV - Whitewash

you maybe able too test the gamma ic voltages usually marked
VG1 VG2 etc etc i think they go to about VG20 if you could test and let us now the voltages we can probably advise more.

[budm]

Re: Samsung LA37B530P7F LED TV - Whitewash

I would say it has bad GAMMA Voltages.

[dskall]

Re: Samsung LA37B530P7F LED TV - Whitewash

You could post your VG1-VG22 voltages in order. They are scattered all over board.

[TheXFool]

Re: Samsung LA37B530P7F LED TV - Whitewash

Thanks for your help thus far. Please see results below.
Voltages were all +_ 0.02 on the left and right boards of the panel also.

T-CON - Volts
VG1 - 15.21
VG2 - 14.96
VG4 - 12.35
VG6 - 10.67
VG8 - 9.98
VG10 - 7.89
VG11 - 7.64
VG12 - 6.71
VG13 - 6.94
VG15 - 4.81
VG17 - 4.18
VG19 - 2.866
VG21 - 0.325
VG22 - 0.297
-
VGHC - 25.35
VGMA - 15.27
VGL - -6.10

[attainteddragon]

Re: Samsung LA37B530P7F LED TV - Whitewash

gamma voltages are bad.
vgl is good.

so you need to replace this ic, or replace the t-con.

[TheXFool]

Re: Samsung LA37B530P7F LED TV - Whitewash

Thanks.
I shall replace the t-con and see how it goes.

[dskall]

Re: Samsung LA37B530P7F LED TV - Whitewash

It says that chip is a replacement for AS-15

[noledud]

Re: Samsung LA37B530P7F LED TV - Whitewash

search on ebay for tcon repair a few sellers offer a repair service for the AS15

[TheXFool]

Re: Samsung LA37B530P7F LED TV - Whitewash

Hi all again,

So I replaced the t-con board and I am still getting the same whitewashed image across the entire panel.

I have attached the voltage readings with the new board in place, i also took some extra readings with bits disconnected to see if that helps figure it out.

By left and right board disconnected, I mean the two boards found under the panel which connect off the bottom of the t-con board. Right and left sides are when viewed from the back of the tv looking forward.

Thanks.

[attainteddragon]

Re: Samsung LA37B530P7F LED TV - Whitewash

had a look over your voltages and vg13 looks out of range but when you measure it on the panel driver board, it looks better.

bit weird.

i'm just wondering if one of the caps on the driver board is breaking down.

what is the voltage at vg13 without the ribbon cables to the panel attached?

there are meant to be more vg voltages floating around but it is one of those boards that hides them everywhere i guess.

[TheXFool]

Re: Samsung LA37B530P7F LED TV - Whitewash

Next round of measurements.

Table 1 is voltages at T-con with neither voltages attached.
Table 2 is voltages across the two panel boards including the unmarked points just following down the line.

Any further suggestions?

[dskall]

Re: Samsung LA37B530P7F LED TV - Whitewash

VG1 voltage 1v difference between two boards

[TheXFool]

Re: Samsung LA37B530P7F LED TV - Whitewash

Typo sorry.
VG1 is 15.17V on both panel boards

[TheXFool]

Re: Samsung LA37B530P7F LED TV - Whitewash

latest update is if I open the ribbon cable clip on the right hand panel board and manipulate the cable I can occasionally get a perfect picture. Is it
Worth replacing the right panel board?

[dskall]

Re: Samsung LA37B530P7F LED TV - Whitewash

I would examine connector and ribbon closely for damage. Clean contacts as vg13 stills seems wrong

[vinceroger69]

Re: Samsung LA37B530P7F LED TV - Whitewash

the panel boards are bonded to the lcd panel and cant be replaced maybe have a look on it for shorted smd capacitors etc

[saddle_au]

Re: Samsung LA37B530P7F LED TV - Whitewash

Clean the ribbon cable connector and the cable itself with isopropyl alcohol.

-------

If you are about to give up as everything you've tried has not worked and everyone else says its a bad panel, watch the following video. I know it's dealing with double images, but your statement about the image coming good every now and then when you fiddle with the cable when its loose reminded me of this.

www.youtube.com/watch?v=j7vl7-vZEL8.

Blocking some signals from the panel (or the return ones) seems to help panels with internal shorts.