Element ELCHW402 won't turn on

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Noo0b
    Member
    • May 2018
    • 28
    • hell

    #1

    Element ELCHW402 won't turn on

    Hello everyone.
    Thanks or reading.

    This TV started having trouble to power on, and after a while it just would not turn on anymore.
    From my reading research, it's a common issue.

    I tried every solution I found online but its still not good.
    The first couple pictures are of the components I replaced.
    The next two what they looked like on the board before the replacement.
    The following four pictures are from the replaced components already soldered to the power board. As you can see from these pictures, some capacitors have different voltages from the originals, but from what I've read online and technician advice, the big blue cap would be better off with this higher spec and the others would not make a difference. The three legged components have the same spec of the original.
    The soldering on the rear of the board does not look the best but seems firm. The big capacitor has some sort of residue on its solder, please check the next 6 pics.
    The last picture is from the power board disconnected from the TV.
    I followed the instructions from the other posts about this failure, and my results seem preety similar: no 12v on the blue-stripped white cable connector.
    I tested the power button on the main board and the voltage seems to drop from 3,3 V to a value above 1 V, most times around 2.4 V.

    The readings that I have on the stripped connector mentioned above, with the 120VAC power line connected are:
    GND: 0.0 V
    GND: 0.0 V
    STB: 2.1 V
    5V_S: 4.81 V
    5V_S: 4.81 V
    12V: 0.0 V
    12V: 0.0 V
    GND: 0.0 V
    BR1: 0.0 V
    SW: 0.2 V
    GND: 0.0 V
    GND: 0.0 V
    5V_M: 0.0 V
    5V_M: 0.0 V
    The relay clicks.
    The SW voltage was 0.0 V before the parts replacement.
    Measurements done with the black probe on chassis.

    The readings with the 120VAC power line connected and the stripped cable disconnected are:
    GND: 0.0 V
    GND: 0.0 V
    STB: 0.0 V
    5V_S: 4.84 V
    5V_S: 4.84 V
    12V: 0.0 V
    12V: 0.0 V
    GND: 0.0 V
    BR1: 0.0 V
    SW: 0.0 V
    GND: 0.0 V
    GND: 0.0 V
    5V_M: 0.0 V
    5V_M: 0.0 V
    Measurements done with the black probe on chassis.

    The readings with the 120VAC power line connected, the stripped cable disconnected and a 1k resistor between STB and 5V_S are:
    GND: 0.0 V
    GND: 0.0 V
    STB: 0.0 V
    5V_S: 4.83 V
    5V_S: 4.83 V
    12V: 0.0 V
    12V: 0.0 V
    GND: 0.0 V
    BR1: 0.0 V
    SW: 0.0 V
    GND: 0.0 V
    GND: 0.0 V
    5V_M: 0.0 V
    5V_M: 0.0 V
    The relay clicks with the resistor contact.
    Measurements done with the black probe on chassis.

    I believe here's where my problem branches from the other related posts on badcaps.net.
    I have tried the solution that worked for those, replacing the 10uf caps, but it did not produce results here.

    If anyone could share advice on what to do next it would be kindly appreciated.
    Thanks in advance for all.
    Attached Files
    Last edited by Noo0b; 06-05-2018, 06:01 PM.
  • CapLeaker
    Leaking Member
    • Dec 2014
    • 8061
    • Canada

    #2
    Re: Element ELCHW402 won't turn on

    with the PSU turned on, what DC voltage do you get on the main filter capacitor? Check out the repair kit for this PSU at SJ. There are some IC's involved and SMD resistors too.

    Comment

    • Noo0b
      Member
      • May 2018
      • 28
      • hell

      #3
      Re: Element ELCHW402 won't turn on

      Hi CapLeaker,
      Thank you for your reply and the kit tip.
      The big capacitor was at around 200 VDC right after plugging in the AC cord, then slowly discharged.
      Measured with each prong at the correspondent cap terminal at the rear of the PSU.
      Isn't 200 V a bit low for a 250 V capacitor?
      Kind Regards and thanks again.

      Comment

      • budm
        Badcaps Legend
        • Feb 2010
        • 40746
        • USA

        #4
        Re: Element ELCHW402 won't turn on

        The BIG MAIN FILTER CAP (black round cap with 450V rating on it) will not have DC on it until the power relay is turned on until the STB (PS-ON) signal is received from the main board.
        https://www.badcaps.net/forum/attach...4&d=1528240407
        Please provided better focused pictures of the whole top and bottom side of the board, I have a hard time reading any prints the board.
        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

        • Noo0b
          Member
          • May 2018
          • 28
          • hell

          #5
          Re: Element ELCHW402 won't turn on

          Hi budm,
          Thank you for your reply.
          I noticed the capacitor would not charge without the main bundle connected.
          A computer jumper shorted STB to 5V and the voltage on the main cap was 221 VDC.
          Capacitance was 0 uf. Also tried with the probes inverted on it's terminals.
          The power switch did not change STB from 2.1V, and the reading on the STB leg of the 1k resistor connected to 5V was 3.3V.
          I took a bunch of separate pictures of the board, that was the best I could do. I added the pictures from another OP with the same issue, newuser65, since they have far better quality, thanks for him. I Also included the schematics for the board, Thanks to R J for that.
          Kind Regards and thank you all again.
          Attached Files
          Last edited by Noo0b; 06-06-2018, 04:07 AM. Reason: Added the Schematics to the upload list

          Comment

          • budm
            Badcaps Legend
            • Feb 2010
            • 40746
            • USA

            #6
            Re: Element ELCHW402 won't turn on

            How did you go about measuring 221VDC on that main filter cap? Where did you put the meter probes?
            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

            • CapLeaker
              Leaking Member
              • Dec 2014
              • 8061
              • Canada

              #7
              Re: Element ELCHW402 won't turn on

              yeah... these 221V DC on the main filter cap do not make any sense. What exact cap did you measure (C903)?

              Comment

              • Noo0b
                Member
                • May 2018
                • 28
                • hell

                #8
                Re: Element ELCHW402 won't turn on

                Hi,
                Thanks for the replies.
                Sorry for this, I guess I should have remembered that the main filter cap is near the power terminal. I measured C810 instead.
                C913 is at 175.3VDC with the probes to the corresponding terminals on the underside of the board.
                The PSU's main connector STB was jumped to 5V with a PC jumper.
                Thanks again.
                Best regards.

                Comment

                • budm
                  Badcaps Legend
                  • Feb 2010
                  • 40746
                  • USA

                  #9
                  Re: Element ELCHW402 won't turn on

                  I just look again at your reported Voltage readings:
                  The readings with the 120VAC power line connected, the stripped cable disconnected and a 1k resistor between STB and 5V_S are:
                  GND: 0.0 V
                  GND: 0.0 V
                  STB: 0.0 V
                  5V_S: 4.83 V
                  5V_S: 4.83 V
                  12V: 0.0 V
                  12V: 0.0 V
                  GND: 0.0 V
                  BR1: 0.0 V
                  SW: 0.0 V
                  GND: 0.0 V
                  GND: 0.0 V
                  5V_M: 0.0 V
                  5V_M: 0.0 V

                  Something is not making sense, if you do have have 1K resistor between 5VS and the STB pin then the STB pin should not be showing '0 V'.
                  You did indicated that the relay does click, if that the case then the PFC Voltage booster circuit is not working since you only see around 170VDC on the main cap with forced on resistor, so need more in-depth troubleshooting in PFC section.
                  Last edited by budm; 06-06-2018, 02:08 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

                  • Noo0b
                    Member
                    • May 2018
                    • 28
                    • hell

                    #10
                    Re: Element ELCHW402 won't turn on

                    Hi,
                    Thank you for the reply.
                    Good point.
                    Multiple rechecks indicate a consistent 3.3VDC reading.
                    Since no repairs were attempted since that reading, it's probably missing a paste edit.
                    My apologies.
                    Best regards and thanks one more time.

                    Comment

                    • Noo0b
                      Member
                      • May 2018
                      • 28
                      • hell

                      #11
                      Re: Element ELCHW402 won't turn on

                      I noticed that R815 is getting a bit hot and R807 is warm to the touch right after jumping STB to 5VS.
                      I believe those are 5.6k Ohms 5% resistors.
                      They are connected in series with resistance "1" if measured separately and "0" if measured at the external terminals.
                      Here's what they look like:
                      Attached Files

                      Comment

                      • Noo0b
                        Member
                        • May 2018
                        • 28
                        • hell

                        #12
                        Re: Element ELCHW402 won't turn on

                        I'm not sure which cap I should have measured.
                        The biggest cap, located between the heatsinks, C810, is rated 250V and reads 221VDC.
                        The smaller cap located nearest from the power terminal, C913, is rated 450V and reads 175.3VDC.
                        Here's what they look like:
                        Attached Files

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA

                          #13
                          Re: Element ELCHW402 won't turn on

                          C810 in the schematic you provided is rated at 220uF 4500V which is the for the PFC Voltage booster circuit filter cap.
                          I do not see C913 in the schematic.
                          Last edited by budm; 06-06-2018, 08:48 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

                          • Noo0b
                            Member
                            • May 2018
                            • 28
                            • hell

                            #14
                            Re: Element ELCHW402 won't turn on

                            Hi budm,
                            Thanks for the reply.
                            I checked the schematics and C810 is rated 220uF 450V indeed.
                            All the other OPs with this board issue report a 250V C810:
                            Originally posted by budm
                            I think the PFC of 220VDC is OK since the cap C810 is only rated at 250VDC.
                            The cap measured is C903, as CapLeaker mentioned.
                            My apologies for this.
                            Its rated 450V and reads only 175V.
                            If that's an indication of a defective cap, I'll try to find and replace it again.
                            Thanks again and kind regards.

                            Comment

                            • Noo0b
                              Member
                              • May 2018
                              • 28
                              • hell

                              #15
                              Re: Element ELCHW402 won't turn on

                              C903 replaced.
                              No changes, still at 175V

                              Comment

                              • R_J
                                Badcaps Legend
                                • Jun 2012
                                • 9535
                                • Canada

                                #16
                                Re: Element ELCHW402 won't turn on

                                When you jump 5V_S to stb, I suspect the relay turns on (clicks once)?
                                This is a universal input power supply rated 100-240v input, thats why the 450 volt cap. for standby, I take it in hell you have 120 volts a/c? so voltgae on C903 will be 160-175 vdc
                                The voltage on C810 should be 400vdc if the pfc is working
                                Check the voltage across C814 (22uf/50v) in pfc circuit (stb jumped to 5v) and then VZ812, It should be 18 volts on the zener and maybe around 25 volts on c814
                                Last edited by R_J; 06-08-2018, 09:10 PM.

                                Comment

                                • Noo0b
                                  Member
                                  • May 2018
                                  • 28
                                  • hell

                                  #17
                                  Re: Element ELCHW402 won't turn on

                                  Hi,
                                  Thanks for the reply.
                                  The relay clicks alright.
                                  All voltages measured at 120VAC.
                                  Its worth noting that everyone seems to be confused about C810.
                                  The schematics report a 450V Cap
                                  Every other OP with this board @ badcaps.net have a 250V 390uF cap, check my pic.
                                  C814 was replaced along C811 and C812 before the OP.
                                  Check the first picture on the OP and C814 is the fist to the left of the bulged blue poly cap.
                                  C814 readings oscilate from 11.45VDC to 11.77VDC, prongs at the terminals and STB jumped to 5VS.
                                  I had a hard time finding VZ812, so i took my chances and assumed it was VD812, by the PFC circuit on the schematics.
                                  It appears to be marked DAO0 SEF1506.
                                  I measured it with the STB jumped, meter set to 20VDC and the meter beeped intermitently.
                                  I inverted the polarities and it beeped a bit as well.
                                  I changed the meter to Diode mode and the moment I touched the anode with the probe a big flash happened at the rear of the board and the fuse is busted.
                                  Hopefully it's the only damage I caused.
                                  Please look at the picture below to see what it looks like.
                                  Thanks for the attention and best regards.
                                  Attached Files

                                  Comment

                                  • CapLeaker
                                    Leaking Member
                                    • Dec 2014
                                    • 8061
                                    • Canada

                                    #18
                                    Re: Element ELCHW402 won't turn on

                                    Yeah, ok... that’s why there are some weird measurements. First off, when you do measurements with the PSU powers on, you only measure Volts AC and DC. For capacitance, resistance and diode mode, the PSU is unplugged!

                                    I am thinking the PFC isn’t working, because you have no boosted voltage. Check that diode you just fiddled around with for a short. If its shorted, replace it. Check the fets on the PFC for a short. If they are shorted to the gate of the fet, check the driver circuitry too.
                                    Last edited by CapLeaker; 06-09-2018, 04:01 AM.

                                    Comment

                                    • R_J
                                      Badcaps Legend
                                      • Jun 2012
                                      • 9535
                                      • Canada

                                      #19
                                      Re: Element ELCHW402 won't turn on

                                      Here we go again... Why would you check resistance with power applied? Not only did you damage the power supply, you likely damaged your meter.
                                      Attached Files
                                      Last edited by R_J; 06-09-2018, 11:53 AM.

                                      Comment

                                      Related Topics

                                      Collapse

                                      • flysky
                                        Gigabyte H610M S2H V2 help to identify the element.
                                        by flysky
                                        There is a motherboard Gigabyte H610M S2H V2 (DDR5), I can't find boardview
                                        Help to identify the element, marking on the element - C31PH. It stands next to the USB 3.0 and it looks like it is ESD Protect chip. We need a datasheet to this element. Maybe someone has already identified such an element. Help please.​






                                        ...
                                        01-23-2025, 07:21 PM
                                      • EasyGoing1
                                        The best way to drive a heating element?
                                        by EasyGoing1
                                        I've got this circuit that I've been playing with on a breadboard. I'm not happy with it mainly because the MOSFET gets too hot and generally controlling the temp of the heating element with the Arduino has proven to be a little more cumbersome than I would like.

                                        What I would like to know, is what is the best way to set up a circuit like this? The heating element is just a PCB and its going to be mounted under a 3D-printed enclosure that a lizard will use to warm his belly.

                                        This is the general setup that I have now.



                                        This is what the...
                                        01-25-2023, 11:29 AM
                                      • sam_sam_sam
                                        Heater element wire type instead of a fuse when troubleshooting a short circuit DIY
                                        by sam_sam_sam
                                        I was Ollie today which is a close out / surplus outlet store I do not go in there to often because you find things that you should not be tempted by but that is a another story

                                        I saw a small space heater that used a wire type of heater element which I been looking for a while but not really hard mind you but when I saw this I grabbed it I going to go back tomorrow and buy the last one that is like the one I bought today because I need the heater element and the ceramic insulators and more of heat element wire because this one has two different wattage settings one 1300 watts ( tap...
                                        12-16-2023, 08:39 PM
                                      • perfm2
                                        Wson8 spring pin probe WORKS
                                        by perfm2
                                        I couldn't find anywhere on the internet where someone had discussed actually using one of these newer wson8 probes for flashing your Wson8 BIOS chip without removing it from the MB.
                                        I recently ordered one to give it a shot and it actually worked quite well.

                                        The tricky part is obviously keeping the probe pins in place on the exposed Wson8 pads of the MB while reading/writing.
                                        I used a larger binder clip attached to the top of the probe to create a large flat surface, then added about 1lb of weight to it.
                                        This aided greatly in allowing the probe to stay in place...
                                        03-30-2023, 11:19 AM
                                      • sirpsychol
                                        Antec Earthwatts EA-380 smd element type/value
                                        by sirpsychol
                                        While recaping Antec Earthwatts EA-380 I've broke one side of unknown smd element, it have no print, it's flatter and darker than smd capacitors on this board, shaped more like resistor but it's not resistor ofc. Unfortunetly the printed description was under it and element was glued to the board so I cant read/tell the letter before element number too. Have anyone any idea what it is? Maybe is there any diagram of this PSU?

                                        ...
                                        09-03-2023, 07:58 PM
                                      • Loading...
                                      • No more items.
                                      Working...