Vertical lines, kdl-40lx900, i susect 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.

[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?

[Dogcatdog]

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

any ideas?

[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

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

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

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.

[freakaftr8]

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

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

[budwich]

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

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

thanks for the reply,
that line comes and goes independent of temperature or anything else from the environment, also it does not matter if i let it run for good 30mins, its also there when all 4 flex cable/ribbons from the panel to the tcon are connected.
its really random, i tested it if i turn the tv on and off like 50 times it does not matter sometimes its there and sometimes not.
any thoughts?

not sure which was being displayed on the screen for those pictures, but I don't think its good. The pictures are not the "same", right to left versus left to right. There appears to be some "horizontal marking" in one direction that is not there in the other. To me, that would indicate some form of issue with the panel on the horizontal which is not good.

[Dogcatdog]

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

thanks for the reply
so i checked the VCC on the EEPROM 4256BWP its a steady 3.3Volt, the 2 pins which have the voltage jumping up and down, one of them is SCL and the other is SDA i marked them in the picture which i attached, so i wonder can i go ahead and unsolder/lift both of those legs up and see if its the same on both sides? or will that cause some trouble? because i was thinking if i would do that and check the legs on the chip that would mean then its the chip, and if its not on the chip but still same thing happening on the board then the cause is somewhere else, who knows maybe even a regulator or something like that. maybe a wonky smd capacitor

thank you in advance

That's most likely a dual layer board. Most likely the traces are embedded in the middle of the board where you can't see. Unless there's a company out there like shop Jimmy that reprogrammed EEPROM you can't just buy a new chip and replace it it has to be programmed. If you don't have an EPROM reprogrammer there's not much to do except buy a new tcon

[budwich]

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

not sure which was being displayed on the screen for those pictures, but I don't think its good. The pictures are not the "same", right to left versus left to right. There appears to be some "horizontal marking" in one direction that is not there in the other. To me, that would indicate some form of issue with the panel on the horizontal which is not good.

[freakaftr8]

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

That's most likely a dual layer board. Most likely the traces are embedded in the middle of the board where you can't see. Unless there's a company out there like shop Jimmy that reprogrammed EEPROM you can't just buy a new chip and replace it it has to be programmed. If you don't have an EPROM reprogrammer there's not much to do except buy a new tcon

[Dogcatdog]

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

thanks for the reply


so, lets say the eeprom is faulty, do i need to program it? or would an off the shelf replacement work?
i have to check one more time the rest of the pins which are connected to the chip will do that in a few hrs i think

btw. those pins seem to connect to nowhere so i wonder even if its fluctuating the voltage if it matters? i will recheck my statement though

Ok well considering the 4256bwp is the eeprom for the tcon and you have 3.3 volts jumping all over I would consider that either the eeprom is faulty, there is a problem with the receiving end of that voltage which is most likely the ram for the main processor, or you have a faulty voltage regulator for that output voltage. Tcon boards are very finicky when it comes to fluctuating voltages or low voltage on one of the rails

[freakaftr8]

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

Ok well considering the 4256bwp is the eeprom for the tcon and you have 3.3 volts jumping all over I would consider that either the eeprom is faulty, there is a problem with the receiving end of that voltage which is most likely the ram for the main processor, or you have a faulty voltage regulator for that output voltage. Tcon boards are very finicky when it comes to fluctuating voltages or low voltage on one of the rails

[Dogcatdog]

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

thank you for the reply, i took today picture of the panel while the flex cables are disconnected, please see attached pictures

what i meant in post #47 is that when i measure the resistance where it says
34.7 Kohm that the display does not turn black and nothing happens, unlike the other side where i measured 40 KOhm it turns black and when i take the DMM probe away the display looks different, the colors have changed , but not better.


btw. which 3.3V notes are you referring to in the PDF? can you tell me what page you have seen those please?


thank you in advance

OP... are you saying there is degree of "darkness" but its the same regardless of which cable I have disconnected or that one side is darker than the other? Pictures will help.
As freakaftr8 indicates, you still need to look at the varying 3.3v if that is the case.

there are "notes" in the service manual around the 3.3v "stuff" ... not sure why they are there... from the company, from someone troubleshooting and copied onto the "ripped copy of the manual"... ???? anyways, they appear to point to capacitance issues around the 3.3v regulator area... not sure I am reading things right. Anyways, if the 3.3 isn't stable, that is an issue.

[Dogcatdog]

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

thank you very much for the reply, both ic301 and ic303 have about the same temperature, none of them seems more warm then the other, but they are almost cool barely warm i attached a picture of the points where i did
those measurements, just in case so there wont be confusion, it is labeled CN101, so im not sure anymore if those are testing points

thank you in advance

The sounds about right. Your panel is ok. I am under the assumption that you have a bad processor or nvram on the tcon. You still have to look at this fact. Your 3.3v is jumping around. Should be steady. Something loads down the 3.3v feeding the nvram. Is one of those heating up and the other stays cool?

These in question are ic301 and ic303

[budwich]

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

OP... are you saying there is degree of "darkness" but its the same regardless of which cable I have disconnected or that one side is darker than the other? Pictures will help.
As freakaftr8 indicates, you still need to look at the varying 3.3v if that is the case.

there are "notes" in the service manual around the 3.3v "stuff" ... not sure why they are there... from the company, from someone troubleshooting and copied onto the "ripped copy of the manual"... ???? anyways, they appear to point to capacitance issues around the 3.3v regulator area... not sure I am reading things right. Anyways, if the 3.3 isn't stable, that is an issue.

[freakaftr8]

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

The sounds about right. Your panel is ok. I am under the assumption that you have a bad processor or nvram on the tcon. You still have to look at this fact. Your 3.3v is jumping around. Should be steady. Something loads down the 3.3v feeding the nvram. Is one of those heating up and the other stays cool?

These in question are ic301 and ic303

[budwich]

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

ok... not sure what to say... what does "nothing" mean.... you should watch your terms closely. Nothing means "0". High resistance is something else... but certainly not "nothing".

Anyways, you make some interesting observations about the screen when you disconnect one cable depending on the side. Do you have a picture of this. Further are you able to feed a signal to the set? If so, are able to find any test dvd that you can get a well defined pattern displayed to help with evaluating the screen?
Sorry for all the questions but its hard to "see thru your eyes and hands" with the internet between us... :-) and lack of full schematics and design for the set.

Having said that "bit darker" doesn't sound good based on my very limited experience.