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Sony KDL-46EX500 2 blinks, then 6 blinks

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    Sony KDL-46EX500 2 blinks, then 6 blinks

    Hi,

    It is about a Sony KDL-46EX500 that was struck by lightning.
    I did not see any visual damage on it.
    An internet provider box and the Ethernet port of an AppleTV were also out of order.

    My following remarks refer to this schematic ; https://www.badcaps.net/forum/attach...2&d=1378923377
    posted by https://www.badcaps.net/forum/member.php?u=16669.
    Thanks to him :-)

    There was nothing on screen, and after a few seconds, it gave the 2 blinks code.
    As I had no 394V on the C6516 capacitor; I decided to change IC 6501 (CXA 3809M).
    Always the same behaviour, but now, the new IC6501 was heating a lot.
    I found then that the zener diode D6101 (MAZ8056G0LS0 ) had a fix resistance of 8 ohms. So I replaced it, and I finally got +394V on the capacitor.

    Now, things have changed and I get a very weak SONY logo on the screen, and the audio chord associated n the loudspeakers.
    A strong «*buzz*» is coming from T6801 transformer during 1 second or so (the time of SONY logo appearance), then this repeats once more, and all stop with a 6 blinks error code.

    I measure (when Power Supply alone with 1K resistor between pin 1 and 3 of CN6150:

    16,2V at the legs of C6206
    394V at the legs of C6516

    When all cards are connected on the chassis, I measure:

    on CN6150 connector:

    STBY3.3V 3,3V
    AUDIO_12V 12,8V
    REG12V 12,8V
    BL_ERR 3,3V then 0,06V during buzz, then 3,3V, then 0,06 during buzz, then 0V
    BL_ON 0V then 3,26V during buzz, then 0V, then 3,26V during buzz, then 0V
    DIMMER 2,3V during buzz, then 0,3V, then 2,3V during buzz, then 0V
    T-CON_Vcc12V 12,76V
    T_CON_ON 3,3V during buzz

    on the CN6702 connector:

    VCC_12V 12,75V
    LD 12,10V and 12,09V during buzz
    FB 0,04V AC during buzz

    Sorry if I have not been clear…

    I also checked many components, that seem to be OK, especially these that I desoldered before testing:

    Q6501
    Q6502
    Q6601
    Q6602
    Q6603
    Q6604
    Q6301

    So… if you can help me …

    Thanks a lot !

    Christian

    #2
    Re: Sony KDL-46EX500 2 blinks, then 6 blinks

    Check all the diodes on the powerboard.

    Comment


      #3
      Re: Sony KDL-46EX500 2 blinks, then 6 blinks

      Check D6151 and D6152, lots of testing videos on youtube if needed.
      Last edited by nomoresonys; 03-29-2021, 06:01 PM.

      Comment


        #4
        Re: Sony KDL-46EX500 2 blinks, then 6 blinks

        Thank you,
        I'll check these today ...

        Comment


          #5
          Re: Sony KDL-46EX500 2 blinks, then 6 blinks

          Done (unsoldered):

          D6151 :
          _____1st diode __Vf=214mV
          _____2nd diode__Vf=217mV

          D6152 :
          _____1st diode __Vf=195mV
          _____2nd diode__Vf=200mV

          Seems okay, no ?

          I'll check minutely all the components I can on the powerboard...
          Last edited by chrisl32; 03-30-2021, 03:04 AM.

          Comment


            #6
            Re: Sony KDL-46EX500 2 blinks, then 6 blinks

            Those measurements seem a little low but not sure, guess it could be a bad electrolytic cap or two in that area maybe. Check all your solder joints the ones going to transformers and heatsinked components take the most abuse.
            Last edited by nomoresonys; 03-30-2021, 09:46 AM.

            Comment


              #7
              Re: Sony KDL-46EX500 2 blinks, then 6 blinks

              Yes, you're right, but as they are Schottky diodes, it seems to be ok, no ?
              I'll check the electrolytic caps this afternoon. I've already checked all diodes of the board... Solder joints seem also ok. Do you have an idea about the possible cause of the loud buzzing noise coming from the T6801 transformer ? I have no experience in TV electronics ;-)
              Thank you

              Comment


                #8
                Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                All electrolytics caps in that area (and more) checked.
                I'll try to check the optocouplers tomorrow with this kind of circuit :
                Attached Files
                Last edited by chrisl32; 03-31-2021, 10:19 AM.

                Comment


                  #9
                  Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                  The 4 optocouplers checked OK :

                  PH6201
                  PH6302
                  PH6300
                  PH6100 (not connected)

                  Comment


                    #10
                    Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                    Do you know if there is a way to be sure that. in my case, the issue comes from the powerboard (vs balancer board or other...)
                    Thanks
                    Last edited by chrisl32; 04-02-2021, 02:45 AM.

                    Comment


                      #11
                      Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                      Unplug your balancer board, then plug power cord back into powerboard, see if it's still buzzing for a quick check of that.

                      Comment


                        #12
                        Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                        Thank you nomoresonys :-)

                        CN6704 (HV1)- CN6705 (HV2) disconnected
                        and
                        CN6702 disconnected.
                        result : no buzz

                        CN6704 (HV1)- CN6705 (HV2) disconnected
                        and
                        CN6702 connected
                        result : no buzz

                        CN6704 (HV1)- CN6705 (HV2) connected
                        and
                        CN6702 disconnected
                        result : no buzz

                        CN6704 (HV1)- CN6705 (HV2) connected
                        and
                        CN6702 connected
                        result : buzz

                        Comment


                          #13
                          Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                          Some inverter testing there: https://www.youtube.com/watch?v=b36w2GNrH6Y

                          Comment


                            #14
                            Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                            More there, DO HEED the WARNING about the DEADLY VOLTAGES: https://www.youtube.com/watch?v=oE6K4xBVweA

                            Comment


                              #15
                              Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                              On this one he is changing meter settings for certain measurements: https://www.youtube.com/watch?v=8oZnSleucJ0
                              Last edited by nomoresonys; 04-02-2021, 11:02 AM.

                              Comment


                                #16
                                Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                                Thank you very much.
                                I’ll do these tests...
                                Last edited by chrisl32; 04-02-2021, 01:13 PM.

                                Comment


                                  #17
                                  Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                                  Hello,

                                  So I did the tests.
                                  First according to this video :

                                  Originally posted by nomoresonys View Post
                                  Some inverter testing there: https://www.youtube.com/watch?v=b36w2GNrH6Y
                                  In diode mode, I got 0.490 V between legs of each diode (the guy on the video measured 0.422 V )
                                  and 0.600 V when the guy measured also 0.600 V ...

                                  So the same results ...
                                  Last edited by chrisl32; 04-04-2021, 01:50 AM.

                                  Comment


                                    #18
                                    Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                                    Test according to this video :

                                    Originally posted by nomoresonys View Post
                                    On this one he is changing meter settings for certain measurements: https://www.youtube.com/watch?v=8oZnSleucJ0
                                    AC mode, tests points on each of the transformers :

                                    T01______0.09 V
                                    T02______0.20 V
                                    T03______0.13 V
                                    T04______0.13 V
                                    T05______0.22 V
                                    T06______0,16 V
                                    T07______0.18 V
                                    T08______0,14 V
                                    T09______0.18 V
                                    T10______0.17 V
                                    T11______0.13 V
                                    T12______0.06 V

                                    The values on T01 and T12 are low ... but as the guy on the video mentioned that high values as 2.5 volts were showing a problem coming from the CCFL, this is not my case...

                                    in DC mode, I measured 2.3 V offset on the cathode of the diodes...
                                    This values also seems to be good (not high value as 36 V like the guy)...

                                    What do you think ?
                                    Thank you

                                    Comment


                                      #19
                                      Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                                      Not sure how you checked your capacitors but I always suspect electrolytic capacitors first when there's buzzing, specially when the tv is over 10 years old.

                                      Comment


                                        #20
                                        Re: Sony KDL-46EX500 2 blinks, then 6 blinks

                                        Capacitors are more difficult to test because they can look good, still have close to their original capacitance value but have high internal resistance which is where they often fail as they get older. The internal electrolyte dries up.
                                        Without any method to test I suppose substitution is the best way forward.
                                        The simple and cheap component testers readily available on line does make testing them so much easier.
                                        Willing to help but I'm no expert.

                                        Comment

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