Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • beetle1303
    Badcaps Veteran
    • Jul 2019
    • 279
    • Singapore

    #1

    Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

    Sharp TV flashing green light 2x per second at constant rate. Various reset methods do not have any effect on it. Search here and found flashing green 2x per second indicate bad power supply, which I am quite certain now.

    I am seeking help with basic trouble shooting to find the short-circuit on the secondary side that I believe is the cause:

    The main PD connector:
    PD-1 (PNL12V) : 0.02V
    PD-2 (PNL12V) : 0.02V (fluctuating)
    PD-3 (SGRN) : 0V
    PD-4 (SGRN) : 0V
    PD-5 (UR13.2V) : 0.05V (fluctuating)
    PD-6 (UR13.2V) : 0.05V (fluctuating)
    PD-7 (UR13.2V) : 0.05V (fluctuating)
    PD-8 (UR13.2V) : 0.05V (fluctuating)
    PD-9 (SGRN) : 0V
    PD-10 (SGRN) : 0V
    PD-11 (SGRN) : 0V
    PD-12 (SGRN) : 0V
    PD-13 (AC_DET) : 2.5V (fluctuating widely)
    PD-14 (PS_ON) : 2.5V (fluctuating)
    PD-15 (BU5V) : 3V (fluctuating widely)
    PD-16 (PNL_POW) : 0.1V
    PD-17 (NC) : 0V
    PD-18 (NC) : 0V
    PD-19 (DIMMER) : 0V
    PD-20 (NC) : 0V
    PD-21 (OFL) : 0V
    PD-22 (ERROR) : 0.05V (fluctuating)
    PD-23 (NC) : 0V
    PD-24 (SBY) : 0V

    3x Opto-couplers input: 2.5V (fluctuating widely)
    3x Opto-couplers output: 2.5V (fluctuating widely)

    Searched here and learned that fluctuating output voltages and feedback circuitry generally means shorted components causing PWM chip to power-cycling up and down..

    If this is the case - need help to find the short(s).
    I have tested all the capacitors, diode and resistors around the PD connector, all seems to be normal reading on and off circuit.
    What else and where else do I start?
    Attached Files
  • Diah
    Badcaps Legend
    • Feb 2013
    • 6343
    • Germany

    #2
    Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

    [QUOTE=beetle1303;
    PD-13 (AC_DET) : 2.5V (fluctuating widely)
    PD-14 (PS_ON) : 2.5V (fluctuating)
    PD-15 (BU5V) : 3V (fluctuating widely)
    [/QUOTE]

    run the PCB as stand alone... with out any connect to it... it sound the short outside the PCB
    Last edited by Diah; 04-19-2022, 09:33 AM.

    Comment

    • beetle1303
      Badcaps Veteran
      • Jul 2019
      • 279
      • Singapore

      #3
      Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

      Originally posted by Diah
      run the PCB as stand alone... with out any connect to it... it sound the short outside the PCB
      Originally tested with mainboard connected, LED strips not connected.

      Wow @Diah!!
      This is power supply stand-alone:
      PD-1 (PNL12V) : 0V
      PD-2 (PNL12V) : 0V
      PD-3 (SGRN) : 0V
      PD-4 (SGRN) : 0V
      PD-5 (UR13.2V) : 0V
      PD-6 (UR13.2V) : 0V
      PD-7 (UR13.2V) : 0V
      PD-8 (UR13.2V) : 0V
      PD-9 (SGRN) : 0V
      PD-10 (SGRN) : 0V
      PD-11 (SGRN) : 0V
      PD-12 (SGRN) : 0V
      PD-13 (AC_DET) : 0V
      PD-14 (PS_ON) : 0V
      PD-15 (BU5V) : 4.95V
      PD-16 (PNL_POW) : 0.1V
      PD-17 (NC) : 0V
      PD-18 (NC) : 0V
      PD-19 (DIMMER) : 0V
      PD-20 (NC) : 0V
      PD-21 (OFL) : 0V
      PD-22 (ERROR) : 0.08V
      PD-23 (NC) : 0V
      PD-24 (SBY) : 0V

      Opto-couplers 1: input: 1.03V / output: 0.38-042V
      Opto-couplers 2: input: 0V / output: 11.05V
      Opto-couplers 1: input: 0V / output: 0.14V

      So confirmed the short(s) in the mainboard? If so is it possible to attempt tracing it on the mainboard?

      Comment

      • Diah
        Badcaps Legend
        • Feb 2013
        • 6343
        • Germany

        #4
        Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

        Originally posted by beetle1303
        Originally tested with mainboard connected, LED strips not connected.

        Wow @Diah!!
        This is power supply stand-alone:
        you need feed the PCB PS_ON pin from the V. you have at the socket present as STB ( (BU5V) : 4.95V ) then this will be stand alone. runing the PCB with out LED BL and MB

        Comment

        • beetle1303
          Badcaps Veteran
          • Jul 2019
          • 279
          • Singapore

          #5
          Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

          Originally posted by Diah
          you need feed the PCB PS_ON pin from the V. you have at the socket present as STB ( (BU5V) : 4.95V ) then this will be stand alone. runing the PCB with out LED BL and MB
          Is it safe to just jump PD15 to PD-14? or must have a ??ohm resistor in between?

          Comment

          • Diah
            Badcaps Legend
            • Feb 2013
            • 6343
            • Germany

            #6
            Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

            Originally posted by beetle1303
            Is it safe to just jump PD15 to PD-14? or must have a ??ohm resistor in between?
            R considered just in case people missed the pin No. so ab to you.

            Comment

            • beetle1303
              Badcaps Veteran
              • Jul 2019
              • 279
              • Singapore

              #7
              Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

              Originally posted by Diah
              R considered just in case people missed the pin No. so ab to you.
              Jumped PD-15 to PD-14:
              This is power supply stand-alone, without any connection:
              PD-1 (PNL12V) : 0.01V
              PD-2 (PNL12V) : 0.01V
              PD-3 (SGRN) : 0.01V
              PD-4 (SGRN) : 0.01V
              PD-5 (UR13.2V) : 13.05V
              PD-6 (UR13.2V) : 13.05V
              PD-7 (UR13.2V) : 13.05V
              PD-8 (UR13.2V) : 13.05V
              PD-9 (SGRN) : 0.01V
              PD-10 (SGRN) : 0.01V
              PD-11 (SGRN) : 0.01V
              PD-12 (SGRN) : 0.01V
              PD-13 (AC_DET) : 3.27V
              PD-14 (PS_ON) : 4.95V
              PD-15 (BU5V) : 4.95V
              PD-16 (PNL_POW) : 0.11V
              PD-17 (NC) : 0V
              PD-18 (NC) : 0V
              PD-19 (DIMMER) : 0V
              PD-20 (NC) : 0V
              PD-21 (OFL) : 0V
              PD-22 (ERROR) : 0.12V
              PD-23 (NC) : 0V
              PD-24 (SBY) : 0.1V

              Opto-couplers 1: input: 0.99V / output: 2.78V
              Opto-couplers 2: input: 1.08V / output: 0.14V
              Opto-couplers 3: input: 0.15V / output: 0.84V
              Last edited by beetle1303; 04-19-2022, 10:55 AM.

              Comment

              • nomoresonys
                Badcaps Legend
                • Jan 2013
                • 12081
                • U.S.

                #8
                Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                check D7951 diode.

                Comment

                • beetle1303
                  Badcaps Veteran
                  • Jul 2019
                  • 279
                  • Singapore

                  #9
                  Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                  Originally posted by nomoresonys
                  check D7951 diode.
                  D7951 diode:
                  In-circuit: forward: 318 reverse: 1568
                  Off-circuit: forward 310 reverse: open

                  Comment

                  • Diah
                    Badcaps Legend
                    • Feb 2013
                    • 6343
                    • Germany

                    #10
                    Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                    Originally posted by beetle1303
                    Jumped PD-15 to PD-14:
                    This is power supply stand-alone, without any connection:
                    PD-1 (PNL12V) : 0.01V
                    PD-2 (PNL12V) : 0.01V

                    PD-3 (SGRN) : 0.01V
                    PD-4 (SGRN) : 0.01V
                    PD-5 (UR13.2V) : 13.05V
                    PD-6 (UR13.2V) : 13.05V
                    PD-7 (UR13.2V) : 13.05V
                    PD-8 (UR13.2V) : 13.05V

                    PD-9 (SGRN) : 0.01V
                    PD-10 (SGRN) : 0.01V
                    PD-11 (SGRN) : 0.01V
                    PD-12 (SGRN) : 0.01V
                    PD-13 (AC_DET) : 3.27V
                    PD-14 (PS_ON) : 4.95V
                    PD-15 (BU5V) : 4.95V
                    PD-16 (PNL_POW) : 0.11V
                    PD-17 (NC) : 0V
                    PD-18 (NC) : 0V
                    PD-19 (DIMMER) : 0V
                    PD-20 (NC) : 0V
                    PD-21 (OFL) : 0V
                    PD-22 (ERROR) : 0.12V
                    PD-23 (NC) : 0V
                    PD-24 (SBY) : 0.1V

                    Opto-couplers 1: input: 0.99V / output: 2.78V
                    Opto-couplers 2: input: 1.08V / output: 0.14V
                    Opto-couplers 3: input: 0.15V / output: 0.84V
                    good so we do have 13V. ur PCB okay... now you add another jumper use R1K from pin 15 to pin 16 PNL_POW to turn on PNL12V.

                    Comment

                    • beetle1303
                      Badcaps Veteran
                      • Jul 2019
                      • 279
                      • Singapore

                      #11
                      Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                      Originally posted by Diah
                      good so we do have 13V. ur PCB okay... now you add another jumper use R1K from pin 15 to pin 16 PNL_POW to turn on PNL12V.
                      Alright!
                      But got to go scout for the R1K resistor from the stashed PCBs. It's passed midnight, will do this tomorrow morning and report back.

                      Thank you.

                      Comment

                      • nomoresonys
                        Badcaps Legend
                        • Jan 2013
                        • 12081
                        • U.S.

                        #12
                        Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                        better scout 2 more then, you will need to jump ps-on, pnl-pow, ofl and dimmer to bu5v, then you can see if the backlights come on and stay on, if they do then your backlights and powerboard are ok.

                        Comment

                        • beetle1303
                          Badcaps Veteran
                          • Jul 2019
                          • 279
                          • Singapore

                          #13
                          Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                          Originally posted by nomoresonys
                          better scout 2 more then, you will need to jump ps-on, pnl-pow, ofl and dimmer to bu5v, then you can see if the backlights come on and stay on, if they do then your backlights and powerboard are ok.
                          Jumped PD-15 to PD-14; and PD-16, PD-19, and PD-21, each with a 800ohm resistor:
                          This is power supply stand-alone, without any connection:
                          PD-1 (PNL12V) : 11.92V
                          PD-2 (PNL12V) : 11.92V
                          PD-3 (SGRN) : 0.02V
                          PD-4 (SGRN) : 0.02V
                          PD-5 (UR13.2V) : 13.05V
                          PD-6 (UR13.2V) : 13.05V
                          PD-7 (UR13.2V) : 13.05V
                          PD-8 (UR13.2V) : 13.05V
                          PD-9 (SGRN) : 0V
                          PD-10 (SGRN) : 0V
                          PD-11 (SGRN) : 0V
                          PD-12 (SGRN) : 0V
                          PD-13 (AC_DET) : 3.27V
                          PD-14 (PS_ON) : 4.95V
                          PD-15 (BU5V) : 4.95V
                          PD-16 (PNL_POW) : 4.58V
                          PD-17 (NC) : 0.04V
                          PD-18 (NC) : 0.04V
                          PD-19 (DIMMER) : 1.34V
                          PD-20 (NC) : 0.04V
                          PD-21 (OFL) : 1.64V
                          PD-22 (ERROR) : 0.12V
                          PD-23 (NC) : 0.04V
                          PD-24 (SBY) : 0.01V

                          Opto-couplers 1: input: 0.99V / output: 2.78V
                          Opto-couplers 2: input: 1.08V / output: 0.14V
                          Opto-couplers 3: input: 0.15V / output: 0.84V

                          Mounted PS back onto TV, connected LED backlights, powered-on, but nothing happens - no backlight on TV...

                          A quick checked - the big cap shows 403Vdv but all the transformers above it shows no voltages in all the output pins... With a LED tester - all the 14 led strips are mostly 175V, with 2-3 showing 173-174V.

                          What/where else to check?
                          Attached Files

                          Comment

                          • Diah
                            Badcaps Legend
                            • Feb 2013
                            • 6343
                            • Germany

                            #14
                            Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                            yours PCB are fine dont touch it any more.. put it back and show us whole photo of TV back showing how boards connected and photos on your MB and it chassis lable.

                            Comment

                            • beetle1303
                              Badcaps Veteran
                              • Jul 2019
                              • 279
                              • Singapore

                              #15
                              Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                              Originally posted by Diah
                              yours PCB are fine dont touch it any more.. put it back and show us whole photo of TV back showing how boards connected and photos on your MB and it chassis lable.
                              Please see attached - TV Back, MB, and Chasis Label.
                              Attached Files

                              Comment

                              • Diah
                                Badcaps Legend
                                • Feb 2013
                                • 6343
                                • Germany

                                #16
                                Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                                is this DIY TV ??? why the socket which it should be at MB go down and had DIY cable ..

                                you should put every things back as opriginal so you can troubleshooting the MB .
                                Attached Files
                                Last edited by Diah; 04-20-2022, 01:33 AM.

                                Comment

                                • beetle1303
                                  Badcaps Veteran
                                  • Jul 2019
                                  • 279
                                  • Singapore

                                  #17
                                  Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                                  Originally posted by Diah
                                  is this DIY TV ??? why the socket which it should be at MB go down and had DIY cable ..
                                  This is the same PS board that we're working on to check if it is working, with all the jumped wires to measure the voltages of PD connector. When mounted back onto the TV, I kept the jumped wires to see if the TV backlight comes on when powered up.

                                  MB metal plate cover removed just to show how cables are connected.

                                  You want to see the PS to MB cable connected?

                                  Comment

                                  • Diah
                                    Badcaps Legend
                                    • Feb 2013
                                    • 6343
                                    • Germany

                                    #18
                                    Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                                    put every thimngs back as original. and remove load from the MB , mean speaker socket out wifi module if you have also out.. turn on and check if you have the 13V at start up.. if no you need MB in case your BL are 100% fine.

                                    Comment

                                    • beetle1303
                                      Badcaps Veteran
                                      • Jul 2019
                                      • 279
                                      • Singapore

                                      #19
                                      Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                                      Originally posted by Diah
                                      put every thimngs back as original. and remove load from the MB , mean speaker socket out wifi module if you have also out.. turn on and check if you have the 13V at start up.. if no you need MB in case your BL are 100% fine.
                                      With only PD cable connected - now the power led indicator flashing 2x red, constantly.
                                      I connected the display & power cables to T-con board - same flashing 2x red light.

                                      I was curious about LED tester show mostly 175V per strip but I didn't see any led light at the back of TV. So I test again and watch the TV screen - no visible light also even though LED Tester show 175V. Possible to have all the led strips shorted?

                                      Comment

                                      • beetle1303
                                        Badcaps Veteran
                                        • Jul 2019
                                        • 279
                                        • Singapore

                                        #20
                                        Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

                                        With only PD connector on MB, only PD-15 showing 4.96V (and not fluctuating), the rests are 0V... I connected Display and power to T-Con, same readings on PD connector, and everything connected back to MB, still same readings - only PD-15 has 4.96V.

                                        Seems like not connect to MB at all? Or MB is dead?

                                        Comment

                                        Related Topics

                                        Collapse

                                        • Cemal Odabasioglu
                                          MacBook Pro A1707 Motherboard Diagnostic Help – CD3215 heating and Fluctuating Rails
                                          by Cemal Odabasioglu
                                          Hello everyone,

                                          I'm currently diagnosing a MacBook Pro A1707 motherboard that does not power on. I've gathered some data but am stuck and need expert advice.
                                          Note that i'm a beginner in electronics and i'm trying to learn while trying to repair this macbook that my work gave me. I'm really curious and love understanding how thing works and i already learned so much.

                                          Only one usb c port is taking 20v and have 12.5v on PPBUS_G3H. when trying other ports, 2 are not going to 20v and one is going to 20v but the CD3215 is getting really hot.

                                          Observations...
                                          01-14-2025, 03:54 PM
                                        • triplefour
                                          ONN 100012588 Has fluctuating Voltage on PSU 12v
                                          by triplefour
                                          Hello all got another TV here im puzzled by. why cant they all be easy fixes that just need a little love and some tape???

                                          anyway i go to this guys house to look at an ONN 100012588
                                          this is my first time looking at one of these brand of TV's.
                                          TBH i have low expectations because i see ONN as the cheap walmart brand that suddenly popped up selling the cheapest version of all kinds of tech things. and someone sent me a ONN flash drive with some data on it with some recordings they wanted me to check out and it immediately broke and corrupted the data and i was unable to...
                                          09-14-2022, 07:41 PM
                                        • beetle1303
                                          Wine Chiller - SMPS issue - fluctuating voltages
                                          by beetle1303
                                          My wine chiller, TECNO SW-126LCD, is semi-functional - it powers up, can set temperature, and chilled to the set temperature, and cuts off compressor, etc. It however runs very hot.

                                          Upon taken out the PSU and did some basic check - 5V output to LCD panel buttons and display is stable, but there is no 12V output to LED lights, and fans.

                                          Further checks found the secondary side voltage is fluctuating around 8-15V range, but the 7805 regulator seems ok and producing the stable 5V output.

                                          Checking further on the primary side: Incoming line input to bridge...
                                          09-04-2023, 10:33 AM
                                        • ronelex
                                          Macbook Air A1466 Fluctuating 3v supply
                                          by ronelex
                                          Hello
                                          I got this unit with orange light but wont boot up
                                          I notice that its L7560 3.3v supply is fluctuating
                                          this is the reading I got on its PWM U7501 TPS51890A
                                          pin 4- EN1 - 0v
                                          pin 12 - EN - 3.3v Fluctuate
                                          pin 21 - EN2 - 3.3v Fluctuate
                                          pin 22 - vreg3 - 3.3v ok
                                          pin 23 - vin - 8.62V
                                          pin 29 - vreg5- 5v fluctuate

                                          I already check the power rails line in page 62 but I didn't find any short on those lines. I already tried replacing the pwm but same issue.
                                          I hope you can guide me where I can look for the fault of this...
                                          02-07-2023, 04:39 AM
                                        • mferna14
                                          MacBook 12" Retina 820-00045-A PP5V_S0 fluctuating
                                          by mferna14
                                          Hi all., I am working on a MacBook 12" Retina Logic Board # 820-00045-A. It does not turn on. The Amp meter show 20v & the amps are around 0.01 ~ 0.05V . Upon checking all the power rails, till PP5V_S4 all is fine, getting full stable 5V on this rail but when I check PP5V_S0, it is fluctuating 5V , after a sec it goes to 0V & comes back again to 5v. This is happening continously. I checked for any short to GRD in diode mode but none. For where is this PP5V_S0 generated?? No liquid spill, logic board is very clean. Any help or tips will be great appreciated. Thanks
                                          11-10-2022, 04:24 PM
                                        • Loading...
                                        • No more items.
                                        Working...