Vertical lines, kdl-40lx900, i susect tcon

[Dogcatdog]

Re: Vertical lines, kdl-40lx900, i susect tcon

not sure what you mean,do you mean the panel is defect?

put an known input on the screen and look at the result when one cable is removed and then repeat from the other side. If the display has "artifacts" that are "suspicious", it will be obvious. There are all sorts of dvd (and others) with known test patterns (color bars for example) that will help.

As for the problem being there when all the cables are connected... yes that is likely and obvious. The issue is that you appear to get rid of it when you have one of the cables disconnected... that tells me you have an issue with that side.

[Dogcatdog]

Re: Vertical lines, kdl-40lx900, i susect tcon

thank you for the reply

here are some of the tests i have done:
All tests are done with pin/leg 5 and 6
lifted up and disconnected
except the ones with pin 8
Here is what i measured on the IC legs/pins 5&6 both gave me 0v
when hooked up and powered. up.
the below tests are done out of the tv set/no power
there is no continuity between the 2 legs, i.e. open circuit/no short
did that also in reverse polarity, i mean i reversed the probes.
next i measured the continuity to ground.with the negative to ground and checking IC legs/pins 5&6 both give me open circuit./no short.
then i reversed the probes, with red to the ground. and on IC
leg 5 i get 1.606MOhm on leg 6 i get open circuit./no short.
then i went ahead and checked the continuity/put DMM in diode mode to check respective to ground.
red probe to ground and black to pin 5 shows me 655 not sure what that means but it means something and on pin 6
it shows 717, so there is something there. btw. my DMM says
it can only measure up to 20Mohm so maybe thats why it did not
show anything from ground to pin 6.

Hooked up i got on both pads 5 and 6 steady 3.3V
that is the pads on the board with the legs lifted and
disconnected from the board.
rest of tests are done without power.
continuity test:
black on ground, red on pad 5 shows 718, with pad 6
it shows the same 718 reversed i.e.red on ground and black on pad 5 and 6 it shows 370.
checking pad to pad, black to pad 5 red to pad 6 gives 920
and reverse is same, note that is what continuity says.
resistance test:
red on ground black on pad 5 and 6 give 8.3KOhm
same if i reverse the DMM probes.
checking between pad 5 and 6 in both directions with the probes gives me
13.5 Kohm

pin 8 Gives always steady 3.3Volt
no matter if all pins are connected to pads or not

ah yes and with the legs pulled up/disconnected leg 5 and 6 the test points on CN101 read steady 3.3V

i also attached a picture with the explanation.

I don't know how to be sharp tcon board with handle this but I know that there is a procedure that involves shorting the SDA pin of the EEPROM to either VCC or ground to reset it on samsung boards. Look into EEPROM reset on the Internet and look at how the pinout configuration works. I guess at this stage you have nothing to lose

[Dogcatdog]

Re: Vertical lines, kdl-40lx900, i susect tcon

additional test i did was, i tried with only either leg/pin 5 or 6 connected to see what i get and i get steady 3.4 volts both give same, just when i connect/solder them both then i get that jumping from 1.xxVolt to 3.xxVolt, btw the above previously mentioned 3.3V are actually 3.4V also on the pin 1 (VCC)
so could it be that the data on the EEprom is corrupt or defect?
also would a firmware update fix that if the data is corrupt?
i mean the one via USB

[Dogcatdog]

Re: Vertical lines, kdl-40lx900, i susect tcon

is there a way to do the firmware update on sony tvs blind and also without remote control? i dont have the remote control

[Dogcatdog]

Re: Vertical lines, kdl-40lx900, i susect tcon

any ideas?

[Dogcatdog]

Re: Vertical lines, kdl-40lx900, i susect tcon

btw. somebody told me that the exhibited behavior of the eeprom could be normal, i.e. that that is actually a signal.
the person said:
"Well the voltages mentioned were in a reasonable range. If the system was powered the lines could be toggling from high to low at high speed which would make an volt-ohm meter think it was in some mid-range voltage (just a PWM effect). the VOM isn't made to work with high speed duty cycle signals... PWM like, not PWM protocol."
so that could be a normal behavior so am i back to square 1? still not sure if its the mainboard or the tcon?

[freakaftr8]

Re: Vertical lines, kdl-40lx900, i susect tcon

Well that's entirely possible but I've never seen a voltage get dragged down like that. Firmware update usually pertains to just mainboards. Not sure but still think you have a corrupt ic, ram or eeprom.