Sony OLED XBR65A8G no video, PSU problem?

[jrfrancisco712]

So what was the outcome of this TV?

I have the same TV as the OP and didn't know if I should start a new thread or not.

Pretty much the same issue, except instead of a red line down the screen, I get a blank screen. 4 red blinks when powered on. Sometimes I could get it to power on after a hard reset, but just blank screen with sound.

I ran the power board stand alone and got these voltages:
EVDD = 22.05V
TCON_12V = 12.69
REG_12V = 12.75

When I plugged in the TCON and tried to power up without main board attached, I didn't get any picture on the screen. I also tried replacing the TCON board but I still did not get any picture on the screen when doing this test.

Does this mean I have a bad panel? Is EVDD correct at 22.06V or should it be closer to 24V?

[j3scott]

Originally Posted by ceak

Hi, I bought a defective OLED Tv thinking I would just replace the defective board and make it work. The problem was that the TV would turn on with sound but no image. I replaced the TCON first, didn't do anything so I replaced the main board and psu boards too but to my surprise the problem is still there.

How many blinking lights do you have and what color?

[mcl360]

Hello all, thanks for letting me join this forum. (please let me know if I need to start a new thread.

I am having the same issue with my A8G except my TV all of the sudden decided to turn off one day and kept power cycling. Did a reset to factory and got to the register you google account and die and will not turn on anymore. No led indicators before or after the failure.

I have done all the aforementioned steps but my PSB is only pushing 22 volts to the EVVD. I even removed the PSB from the chassis all other voltages are nominal and made the bridge to STANDBY, Power On, TCON_ON, EVVD ON. But like I said only getting 22 V from all EVVD outputs from the PSB. Would this cause my TV not to turn on? On a side note, when I put everything back together and plugged the PSB into the MAIN, the standby voltage disappeared.

Any further insight would be greatly appreciated. Just don't want to buy a PSB and it turn out not to be an issue.
----------------------------Break Break Voltages I recorded-----------------
PSB Removed from chassis
PSB To Main Board
Standby Voltage 3.5

TO VIN and EVDD
None


PSB Removed With Bridge to Standby, Power ON, TCON ON, EVDD ON

2 1
BL_ERR 0 TCON_12_ON N/A
AC_OFF_DET 0.49 EVDD_ON N/A
STBY 3.5 Power ON N/A
GRND GRND
GRND GRND
GRND GRND
REG_12V 12.8 REG_12V 12.8
REG_12V 12.8 REG_12V 12.8
REG_12V 12.8 REG_12V 12.8
REG_12V 12.8 REG_12V 12.8
TO VIN EVDD
TCON_GRND TCON_GRND
TCON_GRND TCON_GRND
TCON_GRND TCON_GRND
TCON_12V 12.8 TCON_12V 12.8
TCON_12V 12.8 TCON_12V 12.8
TCON_12V 12.8 TCON_12V 12.8
EVDD_GRND EVDD_GRND
EVDD_GRND EVDD_GRND
EVDD_GRND EVDD_GRND
EVDD_GRND EVDD_GRND
NC EVDD_grnd
EVDD 22 EVDD 22
EVDD 22 EVDD 22
EVDD 22 EVDD 22
EVDD 22 EVDD 22

[Diah]

Originally Posted by mcl360

Hello all, thanks for letting me join this forum.

yours PCB are fine... if yours sony when every things in place and there no T-CON 12 and EVDD mean the problem at main boards.. however start with
following my post#4 run the panel module as stand alone.

[mcl360]

Originally Posted by Diah

yours PCB are fine... if yours sony when every things in place and there no T-CON 12 and EVDD mean the problem at main boards.. however start with
following my post#4 run the panel module as stand alone.

Thanks for the response. When running panel as stand alone still got blank screen no result. I have ordered a main board so hopefully it's not a shorted screen.

[mcl360]

Originally Posted by Diah

yours PCB are fine... if yours sony when every things in place and there no T-CON 12 and EVDD mean the problem at main boards.. however start with
following my post#4 run the panel module as stand alone.

So I got a brand new main board hooked it up same problem.. Went back to T-CON troubleshooting (unplugged all ribbons (2 to Main 4 others at bottom). Getting correct voltage from PSB to TCON VIA EVDD and VIN. EVDD 22 and VIN 12. Plugged ribbons at bottom back in powered up and with correct voltage going to TCON but the screen is still black. At this point I am at the end of my rope with this TV. Any advice would be appreciated. Is the a panel issue?

[Diah]

Originally Posted by mcl360

So I got a brand new main board hooked it up same problem.. Went back to T-CON troubleshooting (unplugged all ribbons (2 to Main 4 others at bottom). So I noticed that when bridged and getting all power required at PCB and then plugging in the EVDD power remains and getting 22 volts at PCB and at TCON.. However, when I plug in the VIN connector from PSB, I hear a click at PSB and no voltage any where. Is this a bad TCON board?

here some things wrong..
1- you need to disconnect the main board from PCB
2- only disconnect the 2 LVDS between main boards and T-CON
3- all 4 ribbon should be in place between T-CON and panel module
4- make the bridge on PCB as you did before..

[mcl360]

Originally Posted by Diah

here some things wrong..
1- you need to disconnect the main board from PCB
2- only disconnect the 2 LVDS between main boards and T-CON
3- all 4 ribbon should be in place between T-CON and panel module
4- make the bridge on PCB as you did before..

Diah, Thank you very much for responding! I did that and have now verified that I am getting correct voltage from PCB to TCON via EVDD (22 volts) and VIN (12 volts). However, I still have a black screen. The way it died doesn't make me think its the panel.. continually restarting until it would not longer power on (screen and picture were fine). Anything else you can think of that could help me narrow down this problem?

[Diah]

EVDD & VIN voltage correct and the set doesn't shutting down ? if yes..then

remove all jumpers and put back the 2 LVDS in place. then turn on , see if the set turning on ( by remark the optic audio output port ) .. and tell if it remain on and whether you have VIN and EVDD correct

[Diah]

Originally Posted by mcl360

Diah, Thank you very much for responding! I did that and have now verified that I am getting correct voltage from PCB to TCON via EVDD (22 volts) and VIN (12 volts). However, I still have a black screen. The way it died doesn't make me think its the panel.. continually restarting until it would not longer power on (screen and picture were fine). Anything else you can think of that could help me narrow down this problem?

i asked you at my post above to put every things back as it should. and turn on... the sign of turning on the optic audio output port should lid red color.. if you have this mean now the main board working so check the vin and evdd if present on both side of the fuses at the t-con side. if okay too... try to remove load from main boards for exmple disconnect the WiFi module

[mcl360]

Originally Posted by Diah

EVDD & VIN voltage correct and the set doesn't shutting down ? if yes..then

remove all jumpers and put back the 2 LVDS in place. then turn on , see if the set turning on ( by remark the optic audio output port ) .. and tell if it remain on and whether you have VIN and EVDD correct

The EVDD & Vin voltage is correct but the screen is not powering on. I will try steps you said in post below and reply with results

[mcl360]

Originally Posted by Diah

i asked you at my post above to put every things back as it should. and turn on... the sign of turning on the optic audio output port should lid red color.. if you have this mean now the main board working so check the vin and evdd if present on both side of the fuses at the t-con side. if okay too... try to remove load from main boards for exmple disconnect the WiFi module

THANKS again for your continued assistance!

So with the jumpers in place and the 2 LVDS cables unplugged I was able to get the correct voltage to the TCONN board from PSB. However, the screen still would not power on.

After I put everything back to normal configuration. I am back at the same problem.

-No power is being output from the PCB to EVDD. VIN is getting 12v. screen black.
-With PCB plugged back in, verified 12 volts going to main board from PSB. No response when pressing power on button.
-Removed WIFI module, no change. unplugged IR SENSOR no change
-No signal from optical audio to indicate main board power up.

Its like the main board is not calling to turn the power on?

[Diah]

Originally Posted by mcl360

THANKS again for your continued assistance!
Its like the main board is not calling to turn the power on?

i am much concerned now if you are doing the things correct.. because when you are telling me here it couldnt be.. as i am not native english speaker i used to write you with points No. if you followed it we will be close to the issue. nso dont make any jumber .. connect your replament main board to PCB and all other cable 2LVDS / 4Ribbon/EVDD/VIN all in place either the WIFI Module. and turn on

1- consider it may dont turn on imeditly because of the last state in case it was Standby.. so you need manual turn it on.. if it did any time you want toturn off just plug it out from wall socket to remain at the new last state to power on not to go to standby.

2- write here all your messurments on the sockets of PCB include vin and EVDD

[mcl360]

Originally Posted by Diah

i am much concerned now if you are doing the things correct.. because when you are telling me here it couldnt be.. as i am not native english speaker i used to write you with points No. if you followed it we will be close to the issue. nso dont make any jumber .. connect your replament main board to PCB and all other cable 2LVDS / 4Ribbon/EVDD/VIN all in place either the WIFI Module. and turn on

1- consider it may dont turn on imeditly because of the last state in case it was Standby.. so you need manual turn it on.. if it did any time you want toturn off just plug it out from wall socket to remain at the new last state to power on not to go to standby.

2- write here all your messurments on the sockets of PCB include vin and EVDD

With everything back to factory configuration I am not getting any voltage on anything. I am getting very frustrated and will try again tomorrow and provide a full write up of all the troubleshooting I have done thus far.

The most concerning to me is when following your initial steps to power on the screen via the bridge/jumpers did not work, but the PCB and TCON were getting the correct voltage.

Thank you again for your patience. I apologize my steps were not detailed and bulleted. I will provide better write up tomarrow.

[mcl360]

Originally Posted by Diah

i am much concerned now if you are doing the things correct.. because when you are telling me here it couldnt be.. as i am not native english speaker i used to write you with points No. if you followed it we will be close to the issue. nso dont make any jumber .. connect your replament main board to PCB and all other cable 2LVDS / 4Ribbon/EVDD/VIN all in place either the WIFI Module. and turn on

1- consider it may dont turn on imeditly because of the last state in case it was Standby.. so you need manual turn it on.. if it did any time you want toturn off just plug it out from wall socket to remain at the new last state to power on not to go to standby.

2- write here all your messurments on the sockets of PCB include vin and EVDD

Diah as promised attached is a detailed write up of the troubleshooting steps and results. Thank you again for your assistance.

Symptom:
TV randomly restarting with increased frequency overtime until eventually would not power on

Issue: TV will not power on. No LED. No Signal from Optical Audio Out

Troubleshooting:
Task 1: Removed back panel and tested voltages on PSB

Result 1: No voltage present on cable terminals going to main board or T-CONN

Task 2: Removed PSB cables going to main board and TCON board

Result 2: Only voltage present on board terminal to main board was the Standby PIN at 3.5 volts

Task 3: With main board and TCONN power cables removed from those boards, made pigtail to bridge/jump Standby, Power On, TCON ON, EVDD ON

Result 3: Note: When I plugged the pigtail in I could hear an audible click at on PSB board.
Voltages observed below:

*PSB Terminal to Main Board*

Row 2 Volts Row 1 Volts
BL_ERR 0 TCON_12_ON N/A
AC_OFF_DET 0.49 EVDD_ON N/A
STBY N/A Power ON N/A
GRND N/A GRND N/A
GRND N/A GRND N/A
GRND N/A GRND N/A
REG_12V 12.8 REG_12V 12.8
REG_12V 12.8 REG_12V 12.8
REG_12V 12.8 REG_12V 12.8
REG_12V 12.8 REG_12V 12.8

*PSB Terminal to EVDD and VIN*

Row 2 Volts Row 1 Volts
TCON_GRND N/A TCON_GRND N/A
TCON_GRND N/A TCON_GRND N/A
TCON_GRND N/A TCON_GRND N/A
TCON_12V 12.8 TCON_12V 12.8
TCON_12V 12.8 TCON_12V 12.8
TCON_12V 12.8 TCON_12V 12.8
EVDD_GRND N/A EVDD_GRND N/A
EVDD_GRND N/A EVDD_GRND N/A
EVDD_GRND N/A EVDD_GRND N/A
EVDD_GRND N/A EVDD_GRND N/A
NC EVDD_GRND N/A
EVDD 22 EVDD 22
EVDD 22 EVDD 22
EVDD 22 EVDD 22
EVDD 22 EVDD 22

Task 4: Unplugged the two LDVS cables going from TCONN board to Main Board and plugged in pigtail to energize the PSB

Result 4: TCON EVDD terminal was receiving 22 volts from PSB and VIN terminal was receiving 12 volts from PSB. Screen did not power on

Task 5: Ordered new main board and installed and reconnected all connectors. Installed Optical Audio Cable. Powered on and left for 30 mins. Also tried to power on with button and remote.

Result 5: No change. Voltage was null across the board on the PSB terminals to the main power board and TCONN board as it was in Task 1 Result. No signal at optical audio cable. No audible click at power supply.

Task 6: Reinstalled original Main Board and began unplugging components like the WIFI card and IR sensor and plugging in the main power cable to the wall.

Result 6: I was able to read 12 volts coming from the PSB to the MAIN board taking the reading at the main board but am unable to duplicate this result nor did this allow the screen to power on.

It seems like the PSB isn't receiving the signal to energize the Main / TCONN circuits. And even when the TCONN was energized with the bridge/pigtail screen didn't power on.

Any further guidance you could provide would be greatly appreciated.

[Diah]

yours replacment main board which you call it before ( brand new ) is defect or beelong to other serie which it could be the socket on it which connect to PCB had differnet wiring pin asigment rather than the original.

2- yours PCB as i wrote before OK.

3- yours Original main boards ( defect ) no start signal sending to PCB to turn on EVDD & VIN
dont do any things ells just bring working MB.

[mcl360]

Originally Posted by Diah

yours replacment main board which you call it before ( brand new ) is defect or beelong to other serie which it could be the socket on it which connect to PCB had differnet wiring pin asigment rather than the original.

2- yours PCB as i wrote before OK.

3- yours Original main boards ( defect ) no start signal sending to PCB to turn on EVDD & VIN
dont do any things ells just bring working MB.

Thanks for the reply. The new board I ordered from Encompass (https://encompass.com/item/11914122/Sony/A-2229-191-A/) was identical to my old board. I guess its possible I got a bad board. I am going to take it to an actual Sony authorized repair place today and let them deal with it. I don't have the time to keep messing with this. THANK YOU VERY MUCH for help. I will post final results when I get it fixed.

[mcl360]

Originally Posted by Diah

yours replacment main board which you call it before ( brand new ) is defect or beelong to other serie which it could be the socket on it which connect to PCB had differnet wiring pin asigment rather than the original.

2- yours PCB as i wrote before OK.

3- yours Original main boards ( defect ) no start signal sending to PCB to turn on EVDD & VIN
dont do any things ells just bring working MB.

Diah, now that you mention it. There are 3 Main CBAs compatible for this TV. See attachments. Did I order the correct one? Like I said, it looked identical, but now I am second guessing myself.

[Diah]

post very clear focused photos of the socket which it goes to PCB and around of the original and replacement Main boards

[mcl360]

Originally Posted by Diah

post very clear focused photos of the socket which it goes to PCB and around of the original and replacement Main boards

Diah, I took the TV to a repair shop and they indeed confirmed what you said. The main board was bad and had a short in it.

I have confirm that the replacement board I ordered and installed before I took it to them that wouldn't power on was the correct board.

I am trying to make sure the replacement board I ordered was indeed bad before I take the TV back as I do not want to pay them $650 to do something I can do for $300.

All the part website say that you have to perform a firmware update on the board after installing or the TV will not power on. Is this true?

Secondly, the shop was recommending that I get a new Flexible Flat Cable 41P (LVDS cable) part number 1-912-894-11 (because one of the ears on the ribbon torn upon removal from the board but Sony no longer manufactures. Would the same connector (Part Number 1-007-198-11? ) from the next model A8H be compatible?

Original Part: https://encompass.com/item/12297577/Sony/1-912-894-11/
Possible Substitute: https://encompass.com/item/12556227/Sony/1-007-198-11/

Thank you again for your support. I definitely owe you a beer.