Lg oled 55ec930v automatically turns off after 1-2 seconds

[learnmore]

Hi Community,

I've got the above model that activates the relay (clicks) and powers on the LG logo power light on when turned on. It then almost immediately turns off. I not noticed any image on the screen or heard any sound during this brief period.

Checks show:
3.5v on SMPS on (in off state, no other voltages present incl pwr on)
On pressing power button > the 3.5 pwn on voltage, 12v and 24v lines appear on the SMPS connnector between the main the SMPS but then all drop the zero in 1-2 seconds
Disconnecting 24 to TCON connector and powering on shows no change in results
Disconnecting connector between SMPS and mainboard shows no change
Dissconnecting periperals (speakers) shows no change
All caps and diodes on SMPS appear okay
No loose transformer joins observed

[Diah]

Hi Community,

I've got the above model that activates the relay (clicks) and powers on the LG logo power light on when turned on. It then almost immediately turns off. I not noticed any image on the screen or heard any sound during this brief period.

Checks show:
3.5v on SMPS on (in off state, no other voltages present incl pwr on)
On pressing power button > the 3.5 pwn on voltage, 12v and 24v lines appear on the SMPS connnector between the main the SMPS but then all drop the zero in 1-2 seconds
Disconnecting 24 to TCON connector and powering on shows no change in results
Disconnecting connector between SMPS and mainboard shows no change where you did hear that !!!
Dissconnecting periperals (speakers) shows no change
All caps and diodes on SMPS appear okay
No loose transformer joins observed

disconnect the lower LVDS cable between mainboards and T-CON... yours LG will turn on.. sign the optic audio port turn red with blank screen
this cable transfer the SOS Flag from T-CON in case it defect or the Screen OLED module defect or drops more currents..

if yours set will turn on... you need to read over this form more to run the standalone test for t-con and screen module.

[learnmore]

Thanks will do, Im actually looking over a similar post you contributed to :

[learnmore]

disconnect the lower LVDS cable between mainboards and T-CON... yours LG will turn on.. sign the optic audio port turn red with blank screen
this cable transfer the SOS Flag from T-CON in case it defect or the Screen OLED module defect or drops more currents..

if yours set will turn on... you need to read over this form more to run the standalone test for t-con and screen module.

One of your post I saw a link to a pdf to do module and driver test (standalone)---but I can seem to find the post again :/---trying all sorts of searches

[Diah]

here you are.... it could be yours pins assignment different.. but the principle of test are the same

[learnmore]

here you are.... it could be yours pins assignment different.. but the principle of test are the same

Many thanks

[learnmore]

Diah, when I ran TEST 2 according to the document, the relay on the SMPS began and continued clicking aggressively, is the to be expect?
I stopped at this stage and unplugged the AC as I am wondering if I jumped the wrong points. Please see the attached image for where I created a jumper for test two (3.5 to 12v)
FYI Test 1 was successful.

[Diah]

of course wrong
1- main boards should be disconnected from power boards
2- 2 LVDS between mainboards and T-CON driver should be disconnected
jumpers
3.5V to Power on
3.5V to DRV_ON
you should have on the same socket 12 V & round 24V
also you need to have round 24V on T-CON EVDD.... and 12V on the T-con 12V... if there are no 12V on t-con you need to fed it with 12V from the sockts to F1 fuse of 12V rail... the screen will turn on and could see if there are issue with OLED cells

[learnmore]

Okay so progress. I've made the correct jumper connections on the SMPS ant all voltages on the connector (12, 3.5, 24) are present where they should according to the key on the SMPS board. There is 24volts goin to the T-con from the SMPS via the connector joining them. I also found this 24v on the T-con at F70 (next to the connector to SMPS). To get a panel test display should I now be sending 12V to F71 (another fuse next to the T-con to Mainboad connector)? I've attached the service manual for my model if it helps. I also had some more photos of the T-con.

[Diah]

yes fed the 12V to Fuse close to LVDS cable... don't forget main boards should be disconnected from PSU and the LVDS disconnected from T-CON side

[learnmore]

Thanks, connector between PSU and MB disconnected on MB end and jumpers inserted. LVDS to T-CON from MB also disconnected. 12V applied to F71 (fuse on T-CON at LVDS connector) No Panel bars, so I'm guessing possible T-Con issue

[learnmore]

Did the test again, there is actually a 1 vertical bar down the center of the screen--T-con or module, I guess?

[Diah]

Did the test again, there is actually a 1 vertical bar down the center of the screen--T-con or module, I guess?

.

[Davi.p]

My bet is tcon, get one from working set , screen broken in pieces..