Announcement

Collapse
No announcement yet.

Samsung Plasma PN64D7000 Flashing Red LED No Power

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Samsung Plasma PN64D7000 Flashing Red LED No Power

    Hi Guys,

    I have a Samsung Plasma PN64D7000 that has started having the flashing red LED issue on the front with no display. I've looked at a couple other posts here that have similar symptoms, but the troubleshooting doesn't seem to net me any results with my problem. I really like this television set, and I would like to fix it instead of tossing it for an OLED. Hopefully you guys can help me get to the root of the issue. I appreciate any assistance or suggestions anyone may have.

    When I plug the television into power, the red LED on the front flashes 5 times.

    When I push the power button, red LED light just flashes once, but nothing happens.

    I do not hear any noticeable clicks or sounds.

    The green LED on the logic board DOES NOT illuminate or flash at all.

    By visual inspection, there are no obvious scorch marks, blown capacitors, or broken solder joints. I have not removed the boards, so solder inspection is done just from the front side.

    I tested continuity across all fuses, and none seem to be open. It is possible I may have overlooked a fuse as I do not know where they all are located.

    So far I've:

    unplugged the Y-sus and X-sus power cable, no change to behavior
    unplugged the power from only X-sus, no change to behavior
    unplugged Y-sus ribbon cable to logic board, no change to behavior
    unplugged X-sus ribbon cable to logic board, no change to behavior
    unplugged both X-sus and Y-sus ribbon cable to logic board, no change to behavior

    I've tested the voltages with everything plugged in and got the following:

    Vs = 6.7 V
    Va = 0.0 V

    I do not notice any spike or change in Vs or Va during initial power up.

    I also tested the voltages from the PS board to the other boards, here is what I found:

    PS to Logic:

    B5V 5.3 V
    B5V 5.3V
    GND 0.0 V
    Vs_Con 0.0 V
    Ps_On 0.2 V
    Vs_On 0.0 V

    PS to Y-Sus:

    Va 0.0 V
    Va 0.0 V
    GND 0.0 V
    GND 0.0 V
    B15V 15.3 V
    GND 0.0 V
    GND 0.0 V
    Vs 6.7 V
    Vs 6.7 V

    PS to Main:

    B5V 5.3 V
    B15V 15.3 V
    B15V 15.3 V
    GND 0.0 V
    B5V 5.3 V
    B5V 5.3 V
    GND 0.0 V
    GND 0.0 V
    B15V 15.3 V
    GND 0.0 V
    A5V 5.3 V
    Ps_On 0.2 V

    If anyone has any ideas, or what steps I should take next, please let me know. Right now, I'm suspecting an issue with the logic board as the green LED shows no function at all. This in conjuction with no change in behavior from plugging in or unplugging the Y-Sus / X-Sus boards leads me to this conclusion. But I am not an electronics repair guy, so it's just a guess on my part. I also have high resolution photos if anyone would like to see them. I'd need to send those through email. Thank You.
    Attached Files

    #2
    Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

    Originally posted by FrivolousShrimp View Post
    Hi Guys,

    I really like this television set, and I would like to fix it instead of tossing it for an OLED.



    So far I've:

    unplugged the Y-sus and X-sus power cable, no change to behavior
    unplugged the power from only X-sus, no change to behavior
    unplugged Y-sus ribbon cable to logic board, no change to behavior
    unplugged X-sus ribbon cable to logic board, no change to behavior
    unplugged both X-sus and Y-sus ribbon cable to logic board, no change to behavior

    I've tested the voltages with everything plugged in and got the following:

    Vs = 6.7 V
    Va = 0.0 V
    if i had a chance to get an oled, i think that i would take it. :P

    you have listed vs and va when all is hooked up, but do these voltages come up when you disconnect x-main, y-main or buffers?
    WHY CAN'T PHILIPS USE PHILLIPS HEAD SCREWS?

    Comment


      #3
      Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

      Originally posted by attainteddragon View Post
      if i had a chance to get an oled, i think that i would take it. :P

      you have listed vs and va when all is hooked up, but do these voltages come up when you disconnect x-main, y-main or buffers?
      I bought a boat a few months ago, so all the fun money is going towards fishing gear. Offshore equipment is not cheap! I'd like to wait on the OLED if possible.

      I want to say that I tested Vs and Va with the x-main and y-main disconnected, and that there was no change, but I did not write that down in my notebook. My memory recall should be questioned. When I get home tonight, I'll unplug all power connectors to the PS and see what Vs and Va report.

      Thanks!

      Comment


        #4
        Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

        If the voltage on the PS-ON pin coming from the main board to the power supply doesn't rise when the power button is pressed, then you almost certainly have a main board failure. I would not suspect the logic board based on your description. You should be able to jumper pins 3-4 on the logic board to produce test patterns on the screen which would prove that the main board is at fault. I'm unsure if anything else needs to be jumpered on this model to produce the test. Typically, the LVDS cable must also be disconnected. That's the ribbon going from the main board to the logic board.

        Comment


          #5
          Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

          This is a 2011 model so your testing will not indicate fault after 3 seconds from switch on as all shuts down. You have to set up the test in readiness then switch on and immediately note what happens:. As said ps.on and vs.on should be checked and if ok then vs voltage but all within the first 3 seconds. Posts made earlier this year contain info.

          Boat definition = a hole in the water into which you poor money.

          Comment


            #6
            Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

            Originally posted by attainteddragon View Post
            you have listed vs and va when all is hooked up, but do these voltages come up when you disconnect x-main, y-main or buffers?
            I disconnected the X-main and Y-main from the PS and plugged the power back in. There was no change in behavior to Vs or Va.

            Originally posted by aaronwt6 View Post
            If the voltage on the PS-ON pin coming from the main board to the power supply doesn't rise when the power button is pressed, then you almost certainly have a main board failure. I would not suspect the logic board based on your description. You should be able to jumper pins 3-4 on the logic board to produce test patterns on the screen which would prove that the main board is at fault. I'm unsure if anything else needs to be jumpered on this model to produce the test. Typically, the LVDS cable must also be disconnected. That's the ribbon going from the main board to the logic board.
            I will go ahead and try to produce the test patterns tomorrow. I'll also test the PS_On voltage when pressing the power button.

            How does the ribbon cable between the logic and main board disconnect? I'm not familiar with that connector type. I tried squeezing the tabs on the sides and pulling, but it doesn't seem to move. I don't want to break it.

            Originally posted by maxvalutech View Post
            This is a 2011 model so your testing will not indicate fault after 3 seconds from switch on as all shuts down. You have to set up the test in readiness then switch on and immediately note what happens:. As said ps.on and vs.on should be checked and if ok then vs voltage but all within the first 3 seconds. Posts made earlier this year contain info.

            Boat definition = a hole in the water into which you poor money.
            I will go ahead and see what happens with PS_On and Vs_On at startup. I tested Vs and Va when plugging power in, but I noticed no change in voltage with those two points at startup versus staying on.

            Just planning ahead here, but if indeed my mainboard is bad, am I pretty much tossing this television? I've looked around for a BN94-04689C, but it seems that availability anywhere is basically none. Even on Ebay, I just see offers to rebuild boards. No actual functioning ones. Shopjimmy and Encompass parts don't have it either. Does anyone have a source for this?

            The boat is definitely a hole in the water, into which I am throwing ridiculous amounts of money. Fishing is my vice, and I want my boy to grow up in the hobby. When you catch your first tuna. you find it's all worth it!

            Comment


              #7
              Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

              Squeeze on both sides of the tab, push in first, then pull out while holding them the hole time. Sometimes that helps. As far as the board goes, I'd check with PTS electronics about repairing it if you determine that's indeed what the problem is. Well worth the $100-$150 to fix it in my opinion for a nice 64" plasma. I certainly wouldn't toss it if it was mine.

              Comment


                #8
                Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                Originally posted by aaronwt6 View Post
                Squeeze on both sides of the tab, push in first, then pull out while holding them the hole time. Sometimes that helps. As far as the board goes, I'd check with PTS electronics about repairing it if you determine that's indeed what the problem is. Well worth the $100-$150 to fix it in my opinion for a nice 64" plasma. I certainly wouldn't toss it if it was mine.
                I'll go ahead and try removing that ribbon tonight and running the pattern.

                Thanks for the repair center recommendation. If I determine the main board is at fault, I'll ship it to them and try to get it fixed. It is a nice television, and would be a shame to get rid of it.

                I am looking at the Samsung fast track troubleshooting manual, and I need a little clarification on running the test pattern.

                The instructions state:

                Short "power on" pin to circuit ground on power connector to SMPS.


                Does this mean I take pin 1 "Ps_On" and just short it to pin 3 "GND"? I would have thought that a voltage would need to be sent down Ps_On to trigger an action. Instead, the instruction seems to state to short it to ground. I probably just don't understand the sequence on how everything gets turned on.

                Thanks again. I appreciate all the help.

                Comment


                  #9
                  Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                  It can be a bit confusing as some switch on circuits have voltage go low while another in same set may have it go high e.g. ps-on and vs-on. Your set doesn't seem to have vs activating at all but there should be time before auto shut down to see any reaction at switch on. Bit different that vs-on goes via control board.

                  Comment


                    #10
                    Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                    Originally posted by maxvalutech View Post
                    It can be a bit confusing as some switch on circuits have voltage go low while another in same set may have it go high e.g. ps-on and vs-on. Your set doesn't seem to have vs activating at all but there should be time before auto shut down to see any reaction at switch on. Bit different that vs-on goes via control board.
                    So I tried to run the logic board test pattern. When I plugged in the power, there is an audible click, but nothing happens. The screen remains blank. There is no green light illuminated on the logic board, and no red light on the front of the television.

                    I watched Vs when the power is plugged in, but I do not see it jump or rise. I've attached photos showing the test configuration. I verified continuity between pins 1 and 3 on the main power board connector. I also verified continuity between pins 3 and 4 on the logic board. I used a paper clip to jump the pins since it is what I have on hand.

                    I've attached the photos of the test configuration so it can be verified I did it correctly.

                    Any ideas on where to go from here? Thank You.
                    Attached Files

                    Comment


                      #11
                      Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                      Do you get a light flashing on the control board?
                      Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                      For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                      Comment


                        #12
                        Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                        Originally posted by tom66 View Post
                        Do you get a light flashing on the control board?
                        If by control board, you mean the logic board, than no, there is not a flashing light. During the test, there isn't an LED anywhere flashing or illuminating.

                        Comment


                          #13
                          Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                          Originally posted by FrivolousShrimp View Post
                          If by control board, you mean the logic board, than no, there is not a flashing light. During the test, there isn't an LED anywhere flashing or illuminating.
                          I'm referring to this one: https://www.badcaps.net/forum/attach...1&d=1502474021

                          That light should flash whenever the B5.3V is on. Can you test the voltages either side of fuse F2000 on the control board?

                          I call it control board because that is the terminology generally used by Samsung, although they aren't 100% consistent.
                          Last edited by tom66; 08-11-2017, 03:03 PM.
                          Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                          For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                          Comment


                            #14
                            Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                            Originally posted by tom66 View Post
                            I'm referring to this one: https://www.badcaps.net/forum/attach...1&d=1502474021

                            That light should flash whenever the B5.3V is on. Can you test the voltages either side of fuse F2000 on the control board?

                            I call it control board because that is the terminology generally used by Samsung, although they aren't 100% consistent.
                            Thanks Tom. It's good to know the manufacturer nomenclature. I was going off of the terminology on the fast track guide.

                            I will go ahead and test that fuse tonight. Do you know what voltages I should expect to see on it? Also, what kind of fuse is this? I'm not at home right now, so I can't put eyes on it. Going off the photo, it doesn't appear to be a typical cartridge type.

                            I see there are two LEDs on that board. A LED2000 and LED2001. Is one of them red and the other green? And would you happen to know what voltage flows through the LED? I'm figuring if I knew the voltage, I could apply one to verify the lights are operable. I've never seen a LED go bad, but I imagine there is a first for everything.

                            And I'm just kicking ideas around here. I've taken the main board out of the loop by running the logic board pattern test. Is there a way to pull the logic board out of the loop to test the power supply alone? As in, can I kick on Vs without the logic board and see if it's operating properly?

                            Thanks again for all the help.

                            Comment


                              #15
                              Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                              Both of the LEDs are green, I doubt they will have failed, I think normally only one flashes and the other is always lit but I can't be sure.

                              The fuse is a Littelfuse 451 surface mount fuse. I'd expect ~5V both sides of it.

                              You can test the power supply without the control board but right now I'd be more interested to see if or why the control board isn't firing up the power supply.
                              Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                              For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                              Comment


                                #16
                                Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                                Originally posted by tom66 View Post
                                Both of the LEDs are green, I doubt they will have failed, I think normally only one flashes and the other is always lit but I can't be sure.

                                The fuse is a Littelfuse 451 surface mount fuse. I'd expect ~5V both sides of it.

                                You can test the power supply without the control board but right now I'd be more interested to see if or why the control board isn't firing up the power supply.
                                So I tested the fuse labeled F2000. The left side of the fuse, I am seeing 5.3V. The right side of the fuse, I am seeing 0.4V. Going to venture a guess this isn't right.

                                I also tested the resistance, and get some odd results. It starts out at 3 kOhm right after being disconnected from the power, and continues to climb > 15 kOhm after sitting awhile. This seems counter-intuitive as I expected resistance to increase with voltage applied as this would raise temperature. Looking at the specs for the 5A Littlefuse, I should see a cold resistance of 0.0125 Ohms. So something is way off.

                                My multimeter is a cheapo, so I would take the accuracy of readings with a grain of salt. But I would venture to say that the readings I am seeing indicate an issue with the fuse. I'm going to suck it up and buy a proper meter tomorrow.

                                I found the fuse on Amazon and put an order in. They aren't very expensive, so I figure why not. Would it be a poor idea to jumper over the fuse and see if the television turns on? Would you suggest any additional trouble shooting while I await the arrival of a new fuse?

                                Thanks again for all the help.

                                Comment


                                  #17
                                  Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                                  i have jumped fuse's this way with a single strand of quality speaker wire copper witch is around 5 amps at 120.

                                  if you check this out it gives you a basic idea of gauge to amperage.


                                  Comment


                                    #18
                                    Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                                    Don't jumper fuses. Easy way to destroy wiring harnesses or potentially damage the panel in this instance. (Panel is fed by 5V supply for address drivers.)
                                    Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                                    For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                                    Comment


                                      #19
                                      Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                                      you would be better off wiring a small torch globe or 2 in series across the fuse to run a quick test.
                                      WHY CAN'T PHILIPS USE PHILLIPS HEAD SCREWS?

                                      Comment


                                        #20
                                        Re: Samsung Plasma PN64D7000 Flashing Red LED No Power

                                        It's a 5V fuse, a bulb isn't going to reveal anything unfortunately
                                        Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                                        For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                                        Comment

                                        Working...
                                        X