Re: No audio no video no backlight on LG47LX9900
Sir Can you help me to repair my led?...
Ashish_Jamesh
Member
Last Activity: 04-13-2023, 02:16 AM
Joined: 05-07-2016
Location: Gujarat
-
Re: No audio no video no backlight on LG47LX9900
Yesterday I reopen LED for checking the fault. I noticed 1 thing, If I tighten the screw of Main AV Board it stop to work (no backlight no audio nothing just TV turn on and off and respond on remote). If I loose the screw then its works normally but after put the cover back and if cover touch the main AV board it again freeze with backlight give noise and restart. after restart some time display come and some time not. 2 thing I noticed that If i turn off LED then its power indication LED stayed on for more than 3-4...Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
Yup you are right I tried it but tv works mostly perfectly on flat surface but sometimes it cause problem as i mentioned earlier. You can see that issue on my youtube video....Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
Prior there was only a single black line shows on display but after issue on Main
board and T-con I replace both board and noticed 1 green (green-yellow color) color changing line and 1 solid line (very dim to see from distance) on display. I already update its firmware with latest available on LG website.
I m really confused because If I open the tv reconnect mainboard and all its cable connector and put the back cover again then tv works perfectly with only issue of blank screen while changing movies...Last edited by Ashish_Jamesh; 04-25-2017, 06:04 AM.Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
BUDM Finally I repaired my LG LED tv but there is still some issue with it. Like following:
1. When I turn on LED TV it turn on and tv start normally with audio and video but suddenly display went away and only backlight on and some king of short circuit sound coming from the TV and it restart automatically. Same processor continue for few days and sudden it works as good as new led without any issue.
2. I notice that If I wall mount the led it having above mentioned issue but after having...Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
I able to repair mainboard with the help of its schematic diagram. But facing one problem. If pcb of mainboard touch the metal part of led tv panel back light suddenly goes off but if I put it on paper or any non metal material then the tv works perfectly. Anyone have any idea? How can I solve this.Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
BUDM is there any suggestion to turn on backlight signal on?...Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
Psu checked with above mentioned trick, backlight works perfectly. So my psu is ok there may be some issue in main avboard. I have its circuit diagram but i cant understand how to enable drv_on/inverter on signal from this....Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
I searched online and got following:
[url]https://electro-medical.blogspot.in/2015/11/lg-47le8500-power-supply-and-led.html[/url]Re: No audio no video no backlight o...led.html[/url]Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
I search online and got something like this, is it possible?
[url]http://www.justanswer.com/tv-repair/7hjln-lg-42le5300-led-tv-plug-press-power-white.html[/url]
1] Ok, yours is integrated which means your power supply board isn't lighting up the LED backlights
2] There is a separate command line on the plug from the main board to the power board. While LG did not number the pins, nor tell you if the TOP pins are Odd or Even, They did give you a layout of the pins and their positioning in relation...Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
DRV ON=00 BL-ON (Backlights ON) signal is not present may be because of bad main av board. So as per ur opinion PWM and DRV ON signals coming from mainboard to power supply board? Or it is come from PSU to mainboard? My led tv has separate MASTER LED DRIVER Board and SLAVE LED DRIVER Board. So is there any way to repair the board? I checked the board very carefully there is no any burnt/shorted component inside. And as mentioned previously my set turned on and give backlight along with half screen black (with backlight)...Last edited by Ashish_Jamesh; 07-01-2016, 11:33 PM.Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
Connector P-201
NC=0.1V (its value increased to 0.2V, 0.3v after few minutes)
PDM=2.7V
DRV ON=00
Power On=3.3V
Connector P-205
PDM=2.7V
Connector P-204
NC=0.1V (its value increased to 0.2V, 0.3v after few minutes)
PDM=2.7VLast edited by Ashish_Jamesh; 06-30-2016, 11:56 PM.Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
Sir whats the functionality of Pin 1=Error, 2=NC, 3=I-C, 4=PDM?
As per my reading with tv standby mode I got only 3.4v, 24v & 12v line shows 0v.
And after switched on the tv I got 3.4v, 24.3, and 12v....Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
I agree with you sir..as per all red box where they say 24V I got 24.3, and where they say 3.5V I got 3.4V, and where they say 12V I got perfect 12V. I measured this value with power on the TV. Now I will try to read the output again on standby mode. But i have one query that how can i read voltage from all 24pins? Because If I unplugged the connector TV not start....Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
I bought another used good condition cable from local market but still no progress
...
Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
These are few pics of Board of PSU, T-Con, Main A/V, Master LED Driver, Slave LED Driver.......Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
1 question arise here..
If I unplugged the power strip from AVBoard tv doesn't power on.
So I read the voltage with tv on and I got 24.3 instead of 24v, and 3.4v instead of 3.5v, 12v pins give me perfect 12v output.Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
Thanks for reply sir. I will upload high resolution pics as soon as possible.Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
members please reply on my thread if its possible for you.Leave a comment:
-
Re: No audio no video no backlight on LG47LX9900
Pic no.4 shows damaged pins of LVDS cable..I searched for LVDS cable but not found in local market so i cut down the broken lvds cable and trim it and make new pins. after attaching this new modified cable i still not got display. But after removing the cable from Mainboard side I got backlight and display in half left side with half dark black right side. So i thought i will look after this at evening. but at evening when i turn on the tv like in morning but surprisingly i didnt got audio, video and backlight.Leave a comment:
No activity results to display
Leave a comment: