Samsung LE40D503F7W LCD TV - RED image, some lines

[Folxs]

Hi, I searched forum for LE40D503F7W red image and didn't find solution.

I thought that this could be like a gamma IC/AS-15F etc.
But there are just 3 main chips on T-CON, that is not able to deattach from panel.

1. SM4109 - i don't know what that is - no normal Dataseet but this is some LCD chip
2. AMLCD LQF6041TOB-Q1 - also no dataseet but this is some LCD chip (i don't know is this chip programmable or something?)
(24c64 connected to AMLCD chip i think)
3. ISL24835 IRZ - some kind of buffer?

Wich of those chips can cause this kind of red tint? I wuld be guessing between 1. and 2. - but maybe someone more experinced than me can help me out?
Thanks!

[saddle_au]

Re: Samsung LE40D503F7W LCD TV - RED image, some lines

Looking around I think SM4109 is a multiple output switching regulator chip. Maybe Samsung or AUO manufactured replacement of another chip, an RT9979GQW which was also a rough copy of a MAX17122
http://monitor.net.ru/forum/rt9979gq...fo-584968.html
https://www.elektroda.pl/rtvforum/topic2857441.html

I think the ISL24835 is a programmable gamma chip (maybe with dual mode output capability).

PS: (also found another chip SM5101 from the same mob which looks like a pin for pin copy of an AS15 including it's failure mode).

[Folxs]

Re: Samsung LE40D503F7W LCD TV - RED image, some lines

PS: (also found another chip SM5101 from the same mob which looks like a pin for pin copy of an AS15 including it's failure mode).

Where that chip is placed?
Did You see that IC on my photos? Or maybe on some schematics?
This chip is on T-CON or motherboard (mob = motherboard?)?

[Davi.p]

Re: Samsung LE40D503F7W LCD TV - RED image, some lines

First. The photos of the tcon board are taken very badly, multiple ones of the same area, shadow on it.. so redo theese better, an try to edit your first post if possible..
Don't think about gamma chip, it's not related to it the defect..

[Folxs]

Re: Samsung LE40D503F7W LCD TV - RED image, some lines

First. The photos of the tcon board are taken very badly, multiple ones of the same area, shadow on it.. so redo theese better, an try to edit your first post if possible..
Don't think about gamma chip, it's not related to it the defect..

Here We go - there are 6 photos of parts of T-CON

There are main question - which chip is responsible of proper colors?
And second - is that AMLCD chip programmable? I can just buy some chips on aliexpress and just replace them, don't even trying to measure them

[dick_barton]

Re: Samsung LE40D503F7W LCD TV - RED image, some lines

You have a lot of voltage test points which you could measure and see if any are missing
VDD_1.2V
VDD_3.3V
VIN
VDD_1.8V
VSS_-7.5V
VOFFE_-11V
VONE_28V
and there may be more.

[Davi.p]

Re: Samsung LE40D503F7W LCD TV - RED image, some lines

I have done troubleshooting theese days with another user in a forum and the result is not cheering, i have suspected low voltages but it's not, better to test them the same, another suspect i had was bad soldering on main chip, but in this case there is not a BGA so is not so suspicious, third suspect is that the gate voltages (VONE, VOFFE) are not reached up to the side tabs, so could be checked with ohm meter respect to the test points on them (usually them must be **gently** scratched from the green paint)..

[Davi.p]

Re: Samsung LE40D503F7W LCD TV - RED image, some lines

Right to finish the post there's not one only chip responsible of image shape, there are almost 2 in this tcon, AMLCD chip i guess is almost surely not programmable.