Lg oled55b8 t-con question

[Diah]

Did that. Got all voltages. Did the jumpers on pwr_on + 12v on and drv_on. No picture. Tcon hot af

No red light on spdif out no usb power either when all is plugged in as supposed to be and I switch mobo on somehow with remote - need to be patient with that since it does not react correctly.

Just to add when standby light is on 12v is present and all voltages on mb and tcon except 24v.

1- you need step down circuit if you don't have stand by voltage all time >3.3V. , this mean you have rail of 12V which it become low >7V when TV Off just plug in and go high to 12V when MB start and send signal to Power_ON.. so keep the PSU alone just plugged in wall and check which bin have V <7V.
2- you have 2 sockets on between the power boards and T-CON driver boards.
A- white socket is T-CON 12V. this will be active when whrn MB send signal to pin 12VT_ON at PSU
B- Black socket its EVDD >;21V this will be active when MB send signal to PSU at Pin DRV_ON

3 stand alone test for PSU and T-CON driver boards & panel should be done on PSU that Power_ON + V12T_ON & DRV_ON got all together got >3.3V as points 1.

4 for fast test.. every things plug in just disconnect the lower LCDS ( large on ) and turn on... check optic ports and V at PSU. this LVDS transfer SOS signal in case issue at panel or t-con you have... one things more if yours TV (MB) switch on but no V. mean its at sleep mode... need to send via service remote Power_ONLY to turn it on again..,.,. followed with exit to exit the sleep / power Only mode.

[reassor]

1- you need step down circuit if you don't have stand by voltage all time >3.3V. , this mean you have rail of 12V which it become low >7V when TV Off just plug in and go high to 12V when MB start and send signal to Power_ON.. so keep the PSU alone just plugged in wall and check which bin have V <7V.
2- you have 2 sockets on between the power boards and T-CON driver boards.
A- white socket is T-CON 12V. this will be active when whrn MB send signal to pin 12VT_ON at PSU
B- Black socket its EVDD >;21V this will be active when MB send signal to PSU at Pin DRV_ON

3 stand alone test for PSU and T-CON driver boards & panel should be done on PSU that Power_ON + V12T_ON & DRV_ON got all together got >3.3V as points 1.

4 for fast test.. every things plug in just disconnect the lower LCDS ( large on ) and turn on... check optic ports and V at PSU. this LVDS transfer SOS signal in case issue at panel or t-con you have... one things more if yours TV (MB) switch on but no V. mean its at sleep mode... need to send via service remote Power_ONLY to turn it on again..,.,. followed with exit to exit the sleep / power Only mode.

1 - 3.3v is allways present on 12v_on if mb plugged in.If i unplug main board i have 7v instaead of 12v as you said (measured on tcon 12v rail)
2 - figured it out alone
3 - did that no picture - took 3.3v from my regulated psu and bridged all 3 ON signals.
4 - does nothing - no usb power no light on spdif

[Diah]

1 - 3.3v is allways present on 12v_on if mb plugged in.If i unplug main board i have 7v instaead of 12v as you said (measured on tcon 12v rail)
2 - figured it out alone
3 - did that no picture - took 3.3v from my regulated psu and bridged all 3 ON signals.
4 - does nothing - no usb power no light on spdif

yours point 3 if you have all V after doing it.... mean yours point 4 that MB dont work ( MICOM ) dont send the DRV_ON 12VT_ON or its in deep sleep as i said before

[Davi.p]

at least one of the microswitches its for restarting the standby software, not really useful..

Check the photo, is the mosfet connected to GND? If yes i think you can do again the previous test but need to jumper to GND both Drain and source..

[Davi.p]

I don't know OLEDS, my suspicion is that EVSS is a negative pole for the EVDD input, but is not at GND.. it is something like VCOM on LCD.. the mosfet can activate the EVDD potential through the pixels.. maybe it is activated by main board.. in another OLED EVSS is 12V... the mosfet might be jumpered D-S...

[reassor]

yours point 3 if you have all V after doing it.... mean yours point 4 that MB dont work ( MICOM ) dont send the DRV_ON 12VT_ON or its in deep sleep as i said before

Drv_on is off 12v_on is always on even when you just plug it in to the outlet. I didn't bridge with main board plugged into psu. I just checked the signals on the plug pwr_on and 12von is on 3.3 and 3.5 yet standby led is on.

[reassor]

I don't know OLEDS, my suspicion is that EVSS is a negative pole for the EVDD input, but is not at GND.. it is something like VCOM on LCD.. the mosfet can activate the EVDD potential through the pixels.. maybe it is activated by main board.. in another OLED EVSS is 12V... the mosfet might be jumpered D-S...

At first I was directly injecting 23v on that fuse with my own adjustable psu bur on this line with just 12v and me injecting to tcon 23v (unplugged from psu also no mainboard) it only consumes around 3.5w on that line... that's nothing so clearly panel is not waking up.

Will look if that mosfet is open or not.

[Davi.p]

i don't follow you, and i don't know if you are following me..

i correct myself "the mosfet might be jumpered D-S..." must be: " the mosfet might have to be jumpered D-S... i hope is more comprehensible..

[Diah]

Drv_on is off 12v_on is always on even when you just plug it in to the outlet. I didn't bridge with main board plugged into psu. I just checked the signals on the plug pwr_on and 12von is on 3.3 and 3.5 yet standby led is on.

this normal stage... in short words when TV in STB mode the firmware can do its JOB regards to Pixel Refresh for OLEDs cells ..

but when front indicator remain on as STB mode and after you power it on no USB 5V or opric even you disconnect the lower LVDS on T-CON driver boards.... always iz will mean MB didnt start or it start at sleep mode... more i cant explain at this threat when there are child who said he dont know OLED and remain posting.

[reassor]

this normal stage... in short words when TV in STB mode the firmware can do its JOB regards to Pixel Refresh for OLEDs cells ..

but when front indicator remain on as STB mode and after you power it on no USB 5V or opric even you disconnect the lower LVDS on T-CON driver boards.... always iz will mean MB didnt start or it start at sleep mode... more i cant explain at this threat when there are child who said he dont know OLED and remain posting.

I see. So it's like trying to do its thing but just hangs.and remains in that constant state. Cause when I turn it off by remote or holding a button on joy it will stay in standby for a sec then relay turns on 12v comes back led blinks 3 times and remains off after that but no drv_on signal. And no usb / spdif.. guy said they were watching and it just went out. Vid +audio. If it 2as led I would just toss a new mobo in and it would work in 99%of cases. Oled is new to me and people say things like panels shorting etc. Also mobo for this thing is not cheap. I'll probably risk it.

[Diah]

I see. So it's like trying to do its thing but just hangs.and remains in that constant state. Cause when I turn it off by remote or holding a button on joy it will stay in standby for a sec then relay turns on 12v comes back led blinks 3 times and remains off after that but no drv_on signal. And no usb / spdif.. guy said they were watching and it just went out. Vid +audio. If it 2as led I would just toss a new mobo in and it would work in 99%of cases. Oled is new to me and people say things like panels shorting etc. Also mobo for this thing is not cheap. I'll probably risk it.

this part of action related to last state option.. mean when the TV last time plugged out from wall and it was at STB.. the next time when it plugged in wall will go back to same state STB..... if the set turn on and then it plugged out from wall the next state when you plug it in wall will start as before.ON

NO DRV_ON mean there are SOS coming from T-con issue or panel.... if you understand the above clearing of last state option.... and disconnect the lower ( large LVDS ) only you will may have USB 5V
and optic ON

[reassor]

this part of action related to last state option.. mean when the TV last time plugged out from wall and it was at STB.. the next time when it plugged in wall will go back to same state STB..... if the set turn on and then it plugged out from wall the next state when you plug it in wall will start as before.ON

NO DRV_ON mean there are SOS coming from T-con issue or panel.... if you understand the above clearing of last state option.... and disconnect the lower ( large LVDS ) only you will may have USB 5V
and optic ON

It always goes to STB state when plugged in or atleas judging by the led. And yes I understand lvda unplug to block panel state or other tcon error from reaching mainboard. But it does not change anything.

Same reaction to same actions.

No usb no spdif.

[Diah]

It always goes to STB state when plugged in or atleas judging by the led. And yes I understand lvda unplug to block panel state or other tcon error from reaching mainboard. But it does not change anything.

Same reaction to same actions.

No usb no spdif.

direct answer.. it mean MB never start ...so the last sate didn't changed.... if the set response to RC. then you need to try in blind way send IN_STOP command via service RC. after the set goes to STBY unplug it from wall wait a little then plug it in again.

[reassor]

direct answer.. it mean MB never start ...so the last sate didn't changed.... if the set response to RC. then you need to try in blind way send IN_STOP command via service RC. after the set goes to STBY unplug it from wall wait a little then plug it in again.

Thx for help. it guided me in to invest in new mobo. That fixed it
Just reporting for others if they search simmilar problem.