lg 42lc55 7 times blinking and after goes out

[Xristakis795]

hi to all
i have the above model lcd tv
the problem is like the title blinking the green led 7 times after is steady green for 30 seconds i can see picture without backlight used a lens and after i hear something like sound from the speaker i think and the green led goes out with the image of course
thanks in advance

[nomoresonys]

Re: lg 42lc55 7 times blinking and after goes out

need good straight on pictures of every board and one of the whole back as to see how everything is connected and a clear closeup of the map/legend of the powerboard.

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

ok sir
i have take some pictures

[dskall]

Re: lg 42lc55 7 times blinking and after goes out

Need to test backlights.
https://www.badcaps.net/forum/showth...er+testing+cfl

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

thanks for the answer sir
and i believe maby its backlight problem
in my case if you notice from the foto i have two plugs go to the ccfl lights
, but each plug has one wire
how can i connect external a ccfl light for testing the inverter ?
one or two lamp must i connect ?

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

sir
just to be sure
i can test it with one lamp ccfl right ?

[dskall]

Re: lg 42lc55 7 times blinking and after goes out

Looks like 2 circuits. Test one at a time. Appears ground is chassis. Also high voltage.

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

i understood
close circuit with ground of chassis
so you tell me to test only one ccfl with one edge to the plug and the other to chassis of tv
or can i use two ccfl with common edge the chassis ?

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

can i do bypass on the ic backlight so to pass the fault with backlight so i can convert it to led ?

[dskall]

Re: lg 42lc55 7 times blinking and after goes out

https://www.youtube.com/watch?v=q4C_...l=MackoyTechPh

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

thanks one more time for your quick answer
in my case the problem is green led blinking 7 times stabilizing for 10 seconds
almost in this duration i can see picture without backlight with the help of a lens
and after the led goes out and the picture tv goes to protect mode
my question is how can avoid this problem and tv doesnt go to protect mode
if i fix this i can convert it to led i have done again in other tv
is there someone ic responsible for the backlight and to do it bypass ?
i have done in a philips tv lcd and work in lg tv is possible in my case ?

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

hi again in my case the responsible inverter ic is oz9965gn
i read ho can i do bypass but i cant understand because there isn t schematic

(OZ9925GN Protection Remove

We solder the LED on the 13th leg. Protection is disabled. The first element with 13 legs is a capacitor. Here we solder it in parallel.)

can anybody with more experience to help me ?

[lotas]

Re: lg 42lc55 7 times blinking and after goes out

parallel capacitor.

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

and what type led must i use ? i mean characterestic volts ?
the tv isn led is lcd with ccfl lamps

[lotas]

Re: lg 42lc55 7 times blinking and after goes out

Regular red LED

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

do you know voltage ?

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

sir dskall
i found the the schematic of power supply in electrotanya and i have confuse and i wanted from your experience little more help
i thinking to use 2 lamps ccfl T5 for the simulation in the same time and no one each time
my problem is from the plan where i connect the connectors of the lamps
the first lamp the one connector on the plug p401 and the other connector on the capacitor c404 wich connected on the ground with the symbol P or on the trimmer v302 wich connected with the ground
similar the second lamp must i connected between the plug p402 and capacitor c409 or trimmer v302 ?
thanks in advance

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

sorry i want to correct something
the problem finally is the tv at the start is standby
when press the power on blinking the green led 7 times after is steady the green led for 10 seconds approximately
you can see with the help of lens display without backlight and after the tv goes in stand by again
it doesnt goes out as i had tell at the start
does anybody of you similar experience ??

[Xristakis795]

Re: lg 42lc55 7 times blinking and after goes out

Hi to all
I'm coming back to the above TV because I thought the problem was the backlight, but since I don't have ccfl lamps or a tester, I wanted to make a bypass inverter, the specific TV has the ic oz9925gn, I found it on the internet, since it doesn't have an operating manual, I keep the capacitor on pin 13 which is already connected and in parallel I connect a normal LED 2.5-3.5 volt
I connected it and the LED doesn't light up, is this normal?
Please, has anyone done this ic bypass?
because I made the connections as Mr. Lotas advised me from here but the LED didn't light up and the result is the same when I press the power button the green LED flashes 7 times then it stays solid green for a few seconds i can see image with a torch because the backlight missing and then it goes into standby mode the red light turns on lent
can someone help me with this problem?