LG 55B6P OLED No image/sound

[blkrx7]

Good evening,

I've been chasing this for a while and wondered if anyone had run into this scenario.

TV was plugged into a cable-tv box which was damaged by a surge.

TV turns on/off via remote, (tv indicator flashes three times then goes out, as normal) but no image/sound. Pressing power again on the remote shuts it off and the indicator comes back on again.

Power supply (when jumpered) outputs 12v/24v where applicable.

When the TV powers up, I get 12v up to the mainboard, 12v to the tcon, but the 24v rail never fires up (shows 1v). Both the mainboard and tcon get warm (35c), but no voltage on the USB ports, no activity on the network card.

I built the IR blaster via headphone jack, have sent POWER_ONLY wav file, and the TV responds by turning on. No other change.

Have depressed both reset switches on the mainboard (one will shut the tv off if it was on). No other change.

I've replaced the power supply, my next guess is mainboard, except I keep wondering if this is how the set would act with a bad Tcon?

Any thoughts?

TIA,
Paul

[Diah]

Re: LG 55B6P OLED No image/sound

its early to say where the issue of this set... remember you send power_only via your Diy IR. this will make the MB didnt send DRV_ON signal to turn on the 24V.

i would start by make the TV stand alone with out any out source signal. and with yours DIY IR send IN_STOP wave file following it with (0-4-1-3 )from your RC. TV will goes to Stand by... plug it out from wall socket for 1 minute then plug it on again... this enough to reset micon and any fault register.. tell if your screen come up again or not.

[blkrx7]

Re: LG 55B6P OLED No image/sound

Thanks so much Diah,

Following this:

Turn set on with RC
Send in_stop.wav
Type 0413 on RC

The TV does not go back into standby

After the above procedure the TV still responds to the power button on the remote and will shut off normally (ie, hasn't locked up that I can tell).

I've tried a number of other variations, but so far no luck. Just to confirm, I don't need to hit 'enter' after 0413? And the set should be turned on normally, not just power_only correct?

[Diah]

Re: LG 55B6P OLED No image/sound

Thanks so much Diah,

Following this:

Turn set on with RC
Send in_stop.wav
Type 0413 on RC

The TV does not go back into standby

After the above procedure the TV still responds to the power button on the remote and will shut off normally (ie, hasn't locked up that I can tell).

I've tried a number of other variations, but so far no luck. Just to confirm, I don't need to hit 'enter' after 0413? And the set should be turned on normally, not just power_only correct?

it seem the wave didnt play correctly.. however i upload over this forum many time apk to run on any android mobile with IR sender.. its more easy and sure too the command sent out.. any way.. if the wave played will do the job too.

the TV should be ON. you can confirm it from the Optic Audio socket.. the RED LED inside will be on.

after send the wave file give time 4 second then put the 0413... you dont need to press any other key,, as son you put the last key (3 ) the screen will show resetting and its go to stand by ( the indicator at the front will lid on ) so the look of the inter password in case the IN_STOP command sent and received correctly

[blkrx7]

Re: LG 55B6P OLED No image/sound

Good afternoon,

I re-confirmed that the wav file (power_only) does play correctly over the IR LED's and turns the set on (just testing the method), but I don't have any way to confirm the (in_stop) is successfully received, as there is no display or reaction from the set. I'm presuming I have the correct set of wav files, they were downloaded as a set.

The optical audio port has no led lit in it (and I wondered about this) when it's turned on or off. There is also no power on the USB ports. But the main processor on the board is warm to the touch.

I've attached a couple thermal images.On the main board the only heat I can find is from the processor. Tcon is warm, and the 12v side of the power supply is of course warm. When turning the set off with the remote, the mainboard and tcon go cold as expected.

I've repeated the unplug, plug, turn on, in_stop, 0413 several times now, no effect at all.

[Diah]

Re: LG 55B6P OLED No image/sound

The optical audio port has no led lit in it (and I wondered about this) when it's turned on or off. There is also no power on the USB ports. But the main processor on the board is warm to the touch.

I've repeated the unplug, plug, turn on, in_stop, 0413 several times now, no effect at all.

so the set now at block condition.. try this
put back your original power boards if you test it before when bridge it and got 12 &24 v on it

don't use power only command any more.. when the set turn on by its original RC plug it out from wall socket.. insert any Air mouse at usb port and other usb stick with any media content such small movie .mpeg format.. after both inserted at usb ports start remove the mouse left and right and click the left and the right bottom of it many time...while you play this with mouse plug it back in wall socket and keep play... hope it will wake up

[blkrx7]

Re: LG 55B6P OLED No image/sound

Thanks, I've tried every combination of usb drive and air mouse I have on hand in each port, no luck. The ports themselves are dead, no power so i'm not sure anything plugged into them will help. I did confirm both the mouse and drive are read correctly by another LG OLED I have here, so they work.

There is an sw300 switch on the back of the main board, when clicked the tv goes into standby. sw100 nearby has no effect.

I can't seem to find any mainboards for this locally at a price worth trying out, I may have to pack it in on this set

[Diah]

Re: LG 55B6P OLED No image/sound

Thanks, I've tried every combination of usb drive..
I can't seem to find any mainboards for this locally at a price worth trying out, I may have to pack it in on this set

its time to trouble shooting hardware issue on Main boards.. lets start with clear photo on the MB.. and tel chassis No. to trace the missing volts.. hope i own the service manual of yours chassis.

[blkrx7]

Re: LG 55B6P OLED No image/sound

its time to trouble shooting hardware issue on Main boards.. lets start with clear photo on the MB.. and tel chassis No. to trace the missing volts.. hope i own the service manual of yours chassis.

Thanks so much, please see link:

https://1drv.ms/u/s!AkYvRKy_t0NMiYgY...dOwRQ?e=ReW7Un

Board: EBT64292507
Chassis: LJ6 or E#64B (Written in two places)

Some service manuals included with photos in the link. Let me know if you'd like closeups of any one area.

I have a multimeter, small oscilloscope, precision iron, hot-air-rework station on hand.

I neglected to mention the surge came via the HDMI port, but don't recall which one. When I removed it from the wall I just reached around and pulled the HDMI without paying attention to which port it was plugged into. I don't need any inputs to the TV, so there is no problem cutting out the HDMI input side.

[Diah]

Re: LG 55B6P OLED No image/sound

Thanks so much, please see link:

please don't use external link to upload photos.. lets make it easy.. to use the advance option and upload over here in this threat high resolution focused photo on this parts of MB HDMI3 / 4.

as tv on (no led indicator at the front panel ) listed please all voltage you have with pin No on the socket at main boards side

[blkrx7]

Re: LG 55B6P OLED No image/sound

please don't use external link to upload photos.. lets make it easy.. to use the advance option and upload over here in this threat high resolution focused photo on this parts of MB HDMI3 / 4.

Absolutely happy to.

Two angles of the HDMI 3/4 area attached. A couple angles of 1/2 as well.

Original files are stored in the link if you need higher resolution.

Working on getting voltages off of the HDMI sockets now, will be in touch shortly.

[blkrx7]

Re: LG 55B6P OLED No image/sound

HDMI 4 and 3 have the same pattern in voltages:

1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
10 0
11 0
12 0
13 ~3.5
14 0
15 4.5
16 4.5
17 0
18 0
19 0

Pins 2, 5,8,11,17 are grounded, both jacks

[Diah]

Re: LG 55B6P OLED No image/sound

HDMI 4 and 3 have the same pattern in voltages:

Pins 2, 5,8,11,17 are grounded, both jacks

ok do you have 13V on the socket at main boards which it come from power supply?

[blkrx7]

Re: LG 55B6P OLED No image/sound

ok do you have 13V on the socket at main boards which it come from power supply?

I can only easily measure the top of P1000, working at getting access to the bottom.

Currently, I show 12v on:

7, 9, 11, 13, 17, 19 (17-19 should be 3.5 no?)

23 has 3.2v


And HDMI 1/2, same pattern except higher voltages on 15/16, at 4.9v

[Diah]

Re: LG 55B6P OLED No image/sound

let us now explain the function of DDC. before you start with IRON work.
HDMI 3/4 receive the 5V from main processor via IC3306. and you have them.
HDMI 1/2 received 5V direct from main processor ( so you need to check do you have 4.5V as you did for HDMI 3/4 ... in case YES you have V on them..

HDMI 2 had ARC function.. if the set at safe mode mode now (blocked) you need to put the set at stand by mode.. and connect any external HDMI device with ARC function ON at the set HDMI port 2 ( marked with ARC) then turn on the external device.. check your set will turn on or not.

[blkrx7]

Re: LG 55B6P OLED No image/sound

Interesting,

HDMI 2 - ARC nothing happens. I've tried a Nintendo Switch, and Nvidia shield, neither detect anything plugged into them (tv on, or off) and the tv doesn't respond while in standby to turning on the devices.

I plugged a laptop into 1/2, doesn't recognize anything plugged in.

I plugged a laptop into 3/4, and it recognizes an "LG RVU Display" (TV still doesn't respond, no picture/sound), the laptop attempts to mirror the desktop at 1080p (old laptop, may be as high as it goes)

Seems like maybe this was plugged into either HDMI 1 or 2 when it got zapped. I'm encouraged to see a response for 3/4.

[Diah]

Re: LG 55B6P OLED No image/sound

try this keep feeding it with HDMI signal while the set on plug it out from wall socket... press on MB SW3000 (Micon reset) keep pressing it while you plug it back to wall socket.. for at least 5 second..

[blkrx7]

Re: LG 55B6P OLED No image/sound

No change.

I've left the laptop plugged in HDMI 3, mirroring my desktop
Unplugged the set, waited until the standby light went out
Clicked power to ensure it was fully discharged
Held down 3000, plugged in the plug, waited 10 seconds and let 3000 off
Turned on the set, no picture, and the big side of the Power Supply still isn't active

When I click the 3000 while the tv is in standby, the led on the front reacts slightly (flickers for a moment). The TV won't react to the RC for 2-3 seconds after that.

[Diah]

Re: LG 55B6P OLED No image/sound

Man... i wrote first you turn on the set.... after it turn on.. plug it out from wall socket... then press 3000 and keep press then plug it back to wall socket... dont use any key or RC

[blkrx7]

Re: LG 55B6P OLED No image/sound

Sorry,

TV was left on
Removed plug
Pressed and held 3000
Plugged in
Left 3000 down for 5 seconds
Released

Remains in standby, no other changes