SONY KDL-55HX850 : No backlight, no error code, rest OK

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Jojo337
    Member
    • Oct 2020
    • 21
    • FRANCE

    #1

    SONY KDL-55HX850 : No backlight, no error code, rest OK

    Hi all !

    I got a Sony 55HX850 with psu APS-326(ch) and Driver LED ST550RD-S01.
    I don't know what happenned before I get it.

    The TV is working great, except the led backlight that does'nt. Backlight nevers turn on, not even a little flash.

    The TV doesn't show red light errors at start The tv is working, I heard the sound of TV from antenna, menu etc... with the flash of my phone I can see the picture that seems fine (T-con OK ?).

    Fuses from Driver LED ST550RD-S01 seems fine (multimeter beeping : not broken, 0V), and caps of this card too.

    Pins :

    If I disconnect the Driver LED cable (CN6601), nothing changes :
    CN6601 pins (tested on card and psu):
    TV ON :
    Pin 14 : 3.3v
    13 : 3.8v
    12 : 0.6v
    11 : 0.7v
    Others : 0v

    TV OFF
    Pin 11 : 0.7v
    Others : 0v

    TV STARTING
    Like ON
    BUT ALL VLED_VCC (pins 1 2 3 4) go to 0.15v and go back to 0v after 4 seconds.

    If I disconnect CN6401 (to the motherboard), no backlight.
    If I disconnect any other cable, the error leds associated to what I disconnected appears.

    CN6401 (to motherboard) pins :
    TV ON : TV OFF :
    Pin Pin
    28 3.3v 28 3.3v
    27 3v 27 3v
    26 3.3v 26 0v

    23 3.3v 23 3.3v

    20 12.43v 20 0v
    19 12.43v 19 0v
    18 12.53v 18 12.54v
    17 12.53v 17 12.54v
    16 12.53v 16 12.54v
    15 12.53v 15 12.54v
    14 12.53v 14 12.54v
    13 12.53v 13 12.54v
    Others : 0v Others : 0v

    OOF long post !! So anyway I'm in France and ... voila !
    (I tried a shunt pin 5/23/28 but nothing).

    Thanks for the help ! Have a good day.
    Attached Files
  • Diah
    Badcaps Legend
    • Feb 2013
    • 6357
    • Germany

    #2
    Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

    CN6401 pin 5 BL_ON did you have voltage on it when turn on ?
    Last edited by Diah; 10-20-2020, 11:19 AM.

    Comment

    • Jojo337
      Member
      • Oct 2020
      • 21
      • FRANCE

      #3
      Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

      I tested this pin and no, always 0V.
      I tried to do a shunt with POWER_ON and STBY_3.3V but nothing happens with the TV too !

      Comment

      • Diah
        Badcaps Legend
        • Feb 2013
        • 6357
        • Germany

        #4
        Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

        Originally posted by Jojo337
        I tested this pin and no, always 0V.
        I tried to do a shunt with POWER_ON and STBY_3.3V but nothing happens with the TV too !
        disconnect the cable of pins 5 BL-ON from the socket on PSU .. jumper pin 5 with standBy pins via R1K 1/4W or less. then turn on the tv see if BL come on

        Comment

        • Jojo337
          Member
          • Oct 2020
          • 21
          • FRANCE

          #5
          Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

          Originally posted by Diah
          disconnect the cable of pins 5 BL-ON from the socket on PSU .. jumper pin 5 with standBy pins via R1K 1/4W or less. then turn on the tv see if BL come on
          Ok I just ordered some resistors 1kohm 0.25w I will come back when the test will be done ! Thanks

          Comment

          • Jojo337
            Member
            • Oct 2020
            • 21
            • FRANCE

            #6
            Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

            Hi ! So the backlight with the resistor between pin 5 (PSU) and with standby 3.3 doesn't turn on Do you have other ideas ?

            Thanks !

            Comment

            • nomoresonys
              Badcaps Legend
              • Jan 2013
              • 12128
              • U.S.

              #7
              Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

              Not sure how you did it, try UNHOOK cable from powerboard to mainboard leave it off, take one resistor from pin 5 to 3.3 standby and another from pin 28 to the same 3.3 standby, plug power into powerboard, see if the backlights come on and stay on.

              Comment

              • Jojo337
                Member
                • Oct 2020
                • 21
                • FRANCE

                #8
                Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                I inserted the resistor into pin 23 (in addition with original "pin 23, or connector" from cable, detached the connector "pin 3" from the cable and inserted the second pin of the resistor into pin 3 of the PSU. I got 3.3v in the resistor "pin".

                I will try this tomorrow, thanks
                Last edited by Jojo337; 10-27-2020, 01:09 PM.

                Comment

                • nomoresonys
                  Badcaps Legend
                  • Jan 2013
                  • 12128
                  • U.S.

                  #9
                  Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                  Remember with test in post #7 you unhook the whole cable, don't want to accidentally fry anything.

                  Comment

                  • Jojo337
                    Member
                    • Oct 2020
                    • 21
                    • FRANCE

                    #10
                    Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                    Yes, nothin plugged except the "Driver led" cable and the modifications.
                    So after the #7 post test, nothing happens. I heard the "clac" from the PSU, but no backlight.

                    BL_ON is at 3.3v with resistors but no backlight.

                    After the tests, unsoldering the resistors, the tv is like before (turns on, screen and sound OK but no BL).

                    https://img.super-h.fr/images/c4345e...39bd8905c8.jpg
                    (Ok this looks bad, but the picture is after testing and after removing protection between pins/solder points with tape )

                    Comment

                    • nomoresonys
                      Badcaps Legend
                      • Jan 2013
                      • 12128
                      • U.S.

                      #11
                      Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                      Try this, see the one from 23 to 28? take it off at 23 and hook it to 5 and leave the rest the same.

                      Comment

                      • Jojo337
                        Member
                        • Oct 2020
                        • 21
                        • FRANCE

                        #12
                        Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                        There was a mistake in my post #8, it's the pin 5 and not the pin 3.

                        Anyways, pins 28 to 5 with resistor and 5 to 23 with resistor does the same !

                        Comment

                        • nomoresonys
                          Badcaps Legend
                          • Jan 2013
                          • 12128
                          • U.S.

                          #13
                          Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                          Ok, my bad 23 is standby, you may need an additional resistor from pin 2 to 23 also to go along with the other two resistors, so 3 resistors used, so 3 resistors will be on 23 and the other ends will be on pins 2, 5 and 28.
                          Last edited by nomoresonys; 10-28-2020, 01:29 PM.

                          Comment

                          • Jojo337
                            Member
                            • Oct 2020
                            • 21
                            • FRANCE

                            #14
                            Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                            Still nothing with the 3 resistors (STBY3.3, POWER ON, BL_ON and PWM_DIMMER), same reactions (pins are 3.3v)

                            Comment

                            • budm
                              Badcaps Legend
                              • Feb 2010
                              • 40746
                              • USA

                              #15
                              Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                              Your post #1:
                              If I disconnect the Driver LED cable (CN6601), nothing changes :
                              CN6601 pins (tested on card and psu):
                              TV ON :
                              Pin 14 : 3.3v
                              13 : 3.8v
                              12 : 0.6v
                              11 : 0.7v
                              Others : 0v

                              CN6601 per chart on your post #1 Pin 14 is the LED ON (BL-ON) and you do have 3.3V there on pin 14.

                              Since you do not have VLED_VCC for driving the LED driver board, the power supply feeding the VLED needs to be checked.

                              Check fusible resistor R6547.

                              I also need good clear straight shots pictures of the whole top and bottom side of YOUR power supply board, and also the pictures of the whole backside of the TV showing how all the boards are connected together.
                              Please also upload the service manual since you already have it.

                              Pictures provided by shopjimmy.
                              APS-326(ch)_Sony 1-474-385-11 G7 PS
                              Attached Files
                              Last edited by budm; 10-28-2020, 04:23 PM.
                              Never stop learning
                              Basic LCD TV and Monitor troubleshooting guides.
                              http://www.badcaps.net/forum/showthr...956#post305956

                              Voltage Regulator (LDO) testing:
                              http://www.badcaps.net/forum/showthr...999#post300999

                              Inverter testing using old CFL:
                              http://www.badcaps.net/forum/showthr...er+testing+cfl

                              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                              http://s807.photobucket.com/user/budm/library/

                              TV Factory reset codes listing:
                              http://www.badcaps.net/forum/showthread.php?t=24809

                              Comment

                              • Jojo337
                                Member
                                • Oct 2020
                                • 21
                                • FRANCE

                                #16
                                Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                                Hi and thanks you for your help !

                                To be clear, when all cables are connected, BL_ON (CN6401 to main borad) is never 3.3v, even if LED_ON (CN 6601 to driver LED) is ~3.28v.

                                R6547 : Beeping with tester (continuity), 0.001v, 018.5 ohm in multimeter (18,5 ohm so ?), it's written 0.1 ohm on it, is it broken or my test is wrong ??

                                Service manual too big for attachment :
                                Attached Files
                                Last edited by Jojo337; 10-29-2020, 06:49 AM.

                                Comment

                                • Diah
                                  Badcaps Legend
                                  • Feb 2013
                                  • 6357
                                  • Germany

                                  #17
                                  Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                                  Originally posted by Jojo337
                                  Hi and thanks you for your help !

                                  To be clear, when all cables are connected, BL_ON (CN6401 to main borad) is never 3.3v, even if LED_ON (CN 6601 to driver LED) is ~3.28v.
                                  check the Fuse on LED driver boards F2001. if its okay.. ready for risky job to take screen apart. search for other 2 hands help you with this risky job.
                                  Last edited by Diah; 10-29-2020, 08:49 AM.

                                  Comment

                                  • budm
                                    Badcaps Legend
                                    • Feb 2010
                                    • 40746
                                    • USA

                                    #18
                                    Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                                    Originally posted by Jojo337
                                    Hi and thanks you for your help !

                                    To be clear, when all cables are connected, BL_ON (CN6401 to main borad) is never 3.3v, even if LED_ON (CN 6601 to driver LED) is ~3.28v.

                                    R6547 : Beeping with tester (continuity), 0.001v, 018.5 ohm in multimeter (18,5 ohm so ?), it's written 0.1 ohm on it, is it broken or my test is wrong ??

                                    Service manual too big for attachment :
                                    1) Monitor that LED_ON pin of CN6601,it should change state between <1V and > 3V when you turn the TV on and off.

                                    2) Set meter to 200VDC scale, Keep black meter probe on chassis, red probe any one of the any one of the VLED_VCC pin of the CN6601 then turn on the TV while watching the meter to see if you see the Voltage jumps up at all.
                                    Never stop learning
                                    Basic LCD TV and Monitor troubleshooting guides.
                                    http://www.badcaps.net/forum/showthr...956#post305956

                                    Voltage Regulator (LDO) testing:
                                    http://www.badcaps.net/forum/showthr...999#post300999

                                    Inverter testing using old CFL:
                                    http://www.badcaps.net/forum/showthr...er+testing+cfl

                                    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                    http://s807.photobucket.com/user/budm/library/

                                    TV Factory reset codes listing:
                                    http://www.badcaps.net/forum/showthread.php?t=24809

                                    Comment

                                    • Jojo337
                                      Member
                                      • Oct 2020
                                      • 21
                                      • FRANCE

                                      #19
                                      Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                                      Hi !
                                      Originally posted by Diah
                                      check the Fuse on LED driver boards F2001. if its okay.. ready for risky job to take screen apart. search for other 2 hands help you with this risky job.
                                      F2001 : Continuity OK (beeping), 0.001v, 0 ohm

                                      Originally posted by budm
                                      1) Monitor that LED_ON pin of CN6601,it should change state between <1V and > 3V when you turn the TV on and off.

                                      2) Set meter to 200VDC scale, Keep black meter probe on chassis, red probe any one of the any one of the VLED_VCC pin of the CN6601 then turn on the TV while watching the meter to see if you see the Voltage jumps up at all.
                                      1) LED_ON is ~-0v in standby and 3.28v TV on

                                      2) VLED_VCC are 0v in standby, go up to 0.140v EACH 4 VLED_VCC for 2 secs and go down to 0V 3 sec later progessively.

                                      Thanks again !

                                      Comment

                                      • budm
                                        Badcaps Legend
                                        • Feb 2010
                                        • 40746
                                        • USA

                                        #20
                                        Re: SONY KDL-55HX850 : No backlight, no error code, rest OK

                                        Originally posted by Jojo337
                                        Hi !


                                        F2001 : Continuity OK (beeping), 0.001v, 0 ohm



                                        1) LED_ON is ~-0v in standby and 3.28v TV on

                                        2) VLED_VCC are 0v in standby, go up to 0.140v EACH 4 VLED_VCC for 2 secs and go down to 0V 3 sec later progessively.

                                        Thanks again !
                                        1) So BL_ON (LED_ON) control signal is fine.

                                        2) So the LED power supply does not even try to put out anything, I would look into that power supply section, since we do not have the schematic of the power supply, then it will have to be traced out, the SMPS IC for that section need to be checked to see if it is getting VCC to run or not, etc.
                                        Never stop learning
                                        Basic LCD TV and Monitor troubleshooting guides.
                                        http://www.badcaps.net/forum/showthr...956#post305956

                                        Voltage Regulator (LDO) testing:
                                        http://www.badcaps.net/forum/showthr...999#post300999

                                        Inverter testing using old CFL:
                                        http://www.badcaps.net/forum/showthr...er+testing+cfl

                                        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                                        http://s807.photobucket.com/user/budm/library/

                                        TV Factory reset codes listing:
                                        http://www.badcaps.net/forum/showthread.php?t=24809

                                        Comment

                                        Related Topics

                                        Collapse

                                        • Carlos#2003%
                                          Schematic de una Sony VAIO PCG-41217u, Sony VPCSB45FL (MBX-237), 1p-0117j01-a012 mbx-237.
                                          by Carlos#2003%
                                          Buenas mi nombre es carlos me uni al foro porque estoy buscando el schematic de una sony vaio pcg-41217u otras formas de escribirlo son 1p-0117j01-a012 mbx-237 numero de placa revision 1.2 o Sony VPCSB (MBX-237), en fin me gustaria y ayudaria un monton si alguien me puede dar dichi svhematic para hacer las mediciones de una laptop de la mencionada anteriormente(Sony VAIO PCG-41217U) con el fin de repararla dejo de funcionar solo prende el led de la bateria al pulsar el boton de power el disco empiesa a hacer ruido de actividad pero los leds del frontas no reflejan acividad y no enciende la pantalla....
                                          02-15-2024, 07:52 PM
                                        • dkneyle
                                          Sony KDL-46HX850 Can't upgrade/update firmware
                                          by dkneyle
                                          Diagnosed this TV as having a failed main board which I've replaced with one from a KDL 55HX850. They are (supposedly) the same board.

                                          Being 'Smart TV' it requires a firmware reboot when you swap out boards such as T-Con or main board. It starts with a black screen and flashing yellow and green LEDS, indicating it needs that firmware boot. The procedure described all over the web is to put the software into the root directory of a FAT32 formatted USB drive and it should load that up once plugged into USB1 port. But not for me. I can see the LED on the USB chip flash for about...
                                          09-25-2024, 10:44 PM
                                        • Document Archive
                                          Sony VAIO SVF11N1L2E Hybrid (2-in-1) Fit multi-flip Specification for Upgrade or Repair
                                          by Document Archive
                                          This specification for the Sony VAIO SVF11N1L2E Hybrid (2-in-1) can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the SVF11N1L2E boardview and SVF11N1L2E schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download...
                                          09-06-2024, 05:27 AM
                                        • Document Archive
                                          Sony VAIO Duo 11 Hybrid (2-in-1) Duo 11 Specification for Upgrade or Repair
                                          by Document Archive
                                          This specification for the Sony VAIO Duo 11 Hybrid (2-in-1) can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the Duo 11 boardview and Duo 11 schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download for Sony VAIO...
                                          09-06-2024, 05:30 AM
                                        • Document Archive
                                          Sony VAIO SVF15N1D4E Hybrid (2-in-1) Fit multi-flip Specification for Upgrade or Repair
                                          by Document Archive
                                          This specification for the Sony VAIO SVF15N1D4E Hybrid (2-in-1) can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the SVF15N1D4E boardview and SVF15N1D4E schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download...
                                          09-06-2024, 05:27 AM
                                        • Loading...
                                        • No more items.
                                        Working...