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...
Dogcatdog
Senior Member
Last Activity: 08-02-2016, 08:31 AM
Joined: 09-18-2015
Location: NY
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Re: Vertical lines, kdl-40lx900, i susect tcon
any ideas?Leave a comment:
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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 controlLeave a comment:
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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 USBLast edited by Dogcatdog; 11-23-2015, 03:52 AM.Leave a comment:
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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...Leave a comment:
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Re: Vertical lines, kdl-40lx900, i susect tcon
not sure what you mean,do you mean the panel is defect?...Leave a comment:
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Re: Acer G235H Abid (dead) no indicator LED
thanks for the reply
first of all thank you very much for this great advice, i did not know better,
"What you DO need to do is to stop testing as you are without understanding what you are doing. As a basic rule
THE ONLY thing you test with the monitor powered up is voltage!!
NEVER test in diode mode or in resistance mode with the monitor powered"
i appreciate that very much
so i coult test the "small switching transistors"...Leave a comment:
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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?...Leave a comment:
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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...Leave a comment:
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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...Last edited by Dogcatdog; 11-22-2015, 09:09 AM.Leave a comment:
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Re: Acer G235H Abid (dead) no indicator LED
in addition i might have forgotten that the short to ground is only when i check with the DMM with the positive probe to the chassis and the negative to the 5v rail, when i reverse the probes then it is not there, but as soon as i unplug the power cord while positive probe is on the chassis and negative on 5v pin, then the circuit drops to open, that is after a few seconds ca.2-4Leave a comment:
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Re: Acer G235H Abid (dead) no indicator LED
nvm it was a bad solder joint that stopped the PSU/SMPS from working, now it works again, so i went ahead and replaced uz1084l 3.3V, with an identical one, and the symptoms are same, on the in pin(right 5V) i get a short to ground as soon as i plug in the power, is this normal? or is this the problem?please help thank you in advanceLast edited by Dogcatdog; 11-22-2015, 05:24 AM. Reason: mentioned wrong pin, 3.3v actual pin is 5v there is the shortLeave a comment:
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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...Last edited by Dogcatdog; 11-22-2015, 01:28 AM.Leave a comment:
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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...Last edited by Dogcatdog; 11-22-2015, 01:27 AM.Leave a comment:
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Re: Vertical lines, kdl-40lx900, i susect tcon
did same measurements with power on. i attached picture...Leave a comment:
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Re: Vertical lines, kdl-40lx900, i susect tcon
i just did what you asked, the far right one is disconnected and the other 3 flex connected gives me the same side blank white i.e. 1/4 of the panel, and the rest has same pattern pink/white vertical lines, and the other side around on the far left if i repeat the same, gives me the same, although one of the sides the left one i.e. CN1301 if i disconnect that then the picture next to it is a bit darker then the rest of it, but still same pattern.
also i did the resistance measurements, without power, i attached a picture,...Leave a comment:
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Re: Vertical lines, kdl-40lx900, i susect tcon
thank you very much for the reply, please let me know what kind of measurements i should take, i have tried each of the 4 cables that go from the tcon to the panel as individually connected, when i do this i get washed out bright lines, without anything from the menu or channel visible.
i took the panel apart the other day and tried to apply pressure, to the bonds/flex cables individually, but there was no change what so ever. i will take it apart again one more time if necessary. it was very much a pain in the butt to take...Leave a comment:
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Re: Acer G235H Abid (dead) no indicator LED
so i believe to have found the fault in the mainboard, so i thought before i replace the LDO
uz1084l 3.3V, i thought i will turn it on and test it one more time, and to my surprise now there comes no voltage, so seems like the PSU got something shot. any ideas? i checked the bridge rectifier it seems fine, altough i had ca. 130V so i thought i will replace it with a knows good rectifier and did that, but strangely enough i get same voltage, i guess the rectifier is fine, but who knowsLeave a comment:
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Re: Vertical lines, kdl-40lx900, i susect tcon
thanks for the reply. thats the thing, if you mean component "33300 K028F"
i can not measure the voltage, as soon as i try, the screen turns black, and when i take the dmm measurement lead away then it comes back but it looks different afterwards. when i turn the tv off and on again its same as always....Leave a comment:
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Re: Acer G235H Abid (dead) no indicator LED
and it does not matter if the small power on/off board is connected to the mainboard or not it happens then anyway, but as mentioned above, only when the cord is plugged inLeave a comment:
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