LG 55EC930V OLED - 3 Second Power No Display

[Billsy]

Good evening all

I could do with some help if you don't mind. I've pickup up a LG 55EC930V OLED curved set that clicks on with no display or sound then off after 3 seconds. The LG bezel logo is on for the 3 seconds then fades out. The previous owner said the screen went white then powered off and he assured me there was no screen damage. I have tried a replacement main board and there's no change. So, before I buy a TCON board,
Is there a way to check that the main board isn't in some kind of lock-out mode?
Am I right in thinking DRV-ON is the signal back from the main board and should be 3.5v?
Can I manually apply 3.5v to DRV-ON? What should I expect?

During the 3 seconds of activity the PS is outputting the following:
3.5v = 3.54v
12v = 11.8v
24v = 25v
PWR-ON = 3.4v
DPC = 0
DRV-ON = 0.08v

Thanks for your help
Billsy

[dick_barton]

Re: LG 55EC930V OLED - 3 Second Power No Display

If you disconnect the mainboard does the backlight come on. If not then with the mainboard still disconnected use a 1K resistor and connect between 3.5V and power on and a second 1K resistor between 3.5V and DRV_ON.

[Diah]

Re: LG 55EC930V OLED - 3 Second Power No Display

If you disconnect the mainboard does the backlight come on. If not then with the mainboard still disconnected use a 1K resistor and connect between 3.5V and power on and a second 1K resistor between 3.5V and DRV_ON.

Dear friend dick_barton , this is OLED Set.
disconnect the LCD driver complete from MB ( LVDS) and the Power socket on the left side and turn on.. check it will remain ON ?

[budwich]

Re: LG 55EC930V OLED - 3 Second Power No Display

read thru this thread, is probably your best bet.
https://www.badcaps.net/forum/showth...led+freakaftr8
Further, because of the design of OLED sets and the great potential for the set to "fire", the design is to shut down if there is any issue with the panel, unlike LCD sets which can be powered up in various forms. Hopefully, you will find an answer.

[Diah]

Re: LG 55EC930V OLED - 3 Second Power No Display

there are no special things to trouble shoot OLED TV if you able to repair Smart Mobile

[dick_barton]

Re: LG 55EC930V OLED - 3 Second Power No Display

Hi Diah, I should have taken notice that it was an OLED so no backlights.

[Billsy]

Re: LG 55EC930V OLED - 3 Second Power No Display

If you disconnect the mainboard does the backlight come on. If not then with the mainboard still disconnected use a 1K resistor and connect between 3.5V and power on and a second 1K resistor between 3.5V and DRV_ON.

With the two resisters in place and main board disconnected, the power board stays on with all outputs steady including the 24v to the TCON. Screen remains black.
With the main board connected, tcon receives 0v
With the four panel ribbons disconnected from the tcon, still 0v to tcon

Dear friend dick_barton , this is OLED Set.
disconnect the LCD driver complete from MB ( LVDS) and the Power socket on the left side and turn on.. check it will remain ON ?

I tried this prior to jumping the pins and it had no effect. off after 3 seconds.

read thru this thread, is probably your best bet.
https://www.badcaps.net/forum/showth...led+freakaftr8
Further, because of the design of OLED sets and the great potential for the set to "fire", the design is to shut down if there is any issue with the panel, unlike LCD sets which can be powered up in various forms. Hopefully, you will find an answer.

Thats a big discussion. His fix was replacing the tcon. I might try that but would be nice if I could eliminate a duff panel.

Thanks guys
Please keep the ideas flowing.

[nomoresonys]

Re: LG 55EC930V OLED - 3 Second Power No Display

Do you have voltage on each side of the tcon fuse?

[budwich]

Re: LG 55EC930V OLED - 3 Second Power No Display

IF you follow thru the discussion (and if I follow it), the "bad tcon" was a problem on the NOS panel. Freak then used his "original one" to get the NOS to work... But I don't think he got the original set / panel to work.... at least at the mid point of the thread. He did have to "reset" the main board via the service menu to get it out of lock out" which is something that you should try.

[Diah]

Re: LG 55EC930V OLED - 3 Second Power No Display

would be nice if I could eliminate a duff panel.
Thanks guys
Please keep the ideas flowing.

LG Panel in General the SOS signal return feed go back via the last ribbon cable between driver ( you call it T-CON ) and panel. at yours case as first photo the last one on the right side. disconnected it via trouble shooting always to avoid SOS Sig.

[Billsy]

Re: LG 55EC930V OLED - 3 Second Power No Display

So I just tried to get into the service menu using the AnyMote app on an old IR enabled Galaxy tab. In AnyMote I selected "LG Most Models" and the resulting remote actually has buttons for EZ-ADJUST, INSTART & INSTOP. None of them worked tho, screen stays black, and no voltage to the tcon. The TV is however responding to PWR ON, CH+, CH- and number keys, by way of the bezel logo illuminating then fading out.

[Diah]

Re: LG 55EC930V OLED - 3 Second Power No Display

your tv turn off after the 3 second in protect mode. LG service menu work only when the TV work and you have picture on the screen

[Diah]

Re: LG 55EC930V OLED - 3 Second Power No Display

how about you take out the metal plate on the panel driver ( T-CON ) and post here photo

[Billsy]

Re: LG 55EC930V OLED - 3 Second Power No Display



Rest of pics are rotated by the forum for some reason.













Thanks guys

[Billsy]

Re: LG 55EC930V OLED - 3 Second Power No Display

[tom66]

Re: LG 55EC930V OLED - 3 Second Power No Display

Could you take a picture of the bottom side of the board? Curious about something.

[Diah]

Re: LG 55EC930V OLED - 3 Second Power No Display

EVSS_CON_ out driver IC burned

[Billsy]

Re: LG 55EC930V OLED - 3 Second Power No Display

Here's the back side

[Diah]

Re: LG 55EC930V OLED - 3 Second Power No Display

if i am i will change this board.

[Billsy]

Re: LG 55EC930V OLED - 3 Second Power No Display

Evss_con_ out
From different angle