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Samsung UN39EH5003FXZA won't stay powered off

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    Samsung UN39EH5003FXZA won't stay powered off

    Hello,

    Purchased a broken Samsung UN39EH5003FXZA (Version CD01) to have fun fixing. When I first acquired it, I did not connect any video signals and only plugged it into the wall. The unit booted and showed the “no signal” window and I could navigate all menus and change sources. I unplugged it, connected my over-the-air antenna to the coax, powered it on, got the unit to scan the HDTV channels, and I think then the TV self-shutdown with the melody. When I powered back up (melody), it would show the channel selected on the OSD and after a couple of seconds, it self-shutdown (melody).

    Through trial and error, I determined that if I removed the antenna, I could power on, stay on and navigate the menu, select HDMI and the TV would display the HDMI video source including audio. I even got the unit to display video off the coax if it was standard def (from an old Tivo). As soon as I tried HDTV from the antenna, it self-powered off, never showing any video.

    I downloaded the latest firmware from the Samsung site and installed it. The unit rebooted and I think I did another channel scan. I was now watching HDTV and could select any channel and all appeared to be functional. I watched for over an hour, enjoying the feeling of success!

    …and then I clicked the power button. The unit powered off (melody), and after a couple of seconds, self-powered back on (melody). So I now have a new failure mode. I cannot get the TV to stay in standby. As soon as power is applied, it powers on with the melody. I can watch both over-the-air and HDMI sources for hours, but as soon as I try to power-off, it self-reboots.

    I have monitored the Power_ON signal and as soon as mains power is applied, it goes to 3.5V and the TV powers on. When I try to power-off, it briefly drops to 0V and then back to 3.5V. I am able to pull down the Power_ON signal via a 10K to ground, and the power supply does shutdown. If I disconnect the main board, the Power_ON pin on the power supply is 3.3V.

    I can't remember if the unit stayed off before the update, as that would point back to a firmware issue.

    Coincidently, I've also noticed the the TV will not remember any settings, other than the channels scanned, after it power cycles. So for example, I can watch TV, select channel 2, change the name of the HDMI source to ‘test', and when I power-off (melody), it reboots on its own (melody), and the channel is 41, and the HDMI source name is lost. All settings always reset.

    I suspect that the eprom/flash that stores the settings, must also store the power state. So that if the memory is unable to store the power-off flag, the micro doesn't know to stay powered off. Valid?

    Any insight would be most appreciated. Thank you!

    #2
    Re: Samsung UN39EH5003FXZA won't stay powered off

    Are you able to do a firmware update.
    https://www.samsung.com/ca/support/m...N39EH5003FXZC/
    Willing to help but I'm no expert.

    Comment


      #3
      Re: Samsung UN39EH5003FXZA won't stay powered off

      Originally posted by Hannibal_Hector View Post
      I suspect that the eprom/flash that stores the settings, must also store the power state.
      +1 yours suspect correct

      Comment


        #4
        Re: Samsung UN39EH5003FXZA won't stay powered off

        What is the version number found on the sticker on the back cover of the tv?
        Last edited by nomoresonys; 03-03-2021, 05:35 AM.

        Comment


          #5
          Re: Samsung UN39EH5003FXZA won't stay powered off

          Thank you all for your thoughts...

          @dick_barton, "Are you able to do a firmware update."
          Yes, I did the update and that solved the initial problem, which either created or revealed a new one.


          @Diah, Now I need to figure out how to replace the flash chip. I haven't been able to find a source for a pre-programmed (I'm guessing that just means formatted appropriately.), so my alternative is to purchase a blank, pull the 'bad' one, read it, and write it to the new one. Of course, I may just be copying corrupted data. I could try to figure out what file format they're using and maybe try to re-format. Maybe I can purchase a donor board.

          @nomoresonys, The version is CD01

          Comment


            #6
            Re: Samsung UN39EH5003FXZA won't stay powered off

            Originally posted by Hannibal_Hector View Post
            _
            its always advised after any firmware update need to reset the TV as hard reset from service menu.. this help allot to bring every things in it place

            Comment


              #7
              Re: Samsung UN39EH5003FXZA won't stay powered off

              EEPROM there: https://www.ebay.com/itm/Samsung-BN9...Cclp%3A2334524

              Comment


                #8
                Re: Samsung UN39EH5003FXZA won't stay powered off

                @Diah, the factory reset from the diagnostic menu didn't do it. Haven't tried the service menu, and I need to figure out how to get in there. Hopefully, it doesn't require the tv to be in standby!

                @nomoresonys, that eeprom is the popular one, and I think it stores the configuration of the device, like the resolution, size, types of boards, etc. Yes? I am very curious about the other eeprom next to it, the so-8 size 24512RP. What does it store? I do not find mention of that one anywhere, with respect to this model. I want to put the scope on it and see when the SoC accesses it. I also want to dump it and see if I can write to it. It does have 3.3V on pins 1 & 8, so its getting juice.

                Comment


                  #9
                  Re: Samsung UN39EH5003FXZA won't stay powered off

                  service menu
                  There are many service menu codes depending on your Samsung TV model. You can try each code below until it works.


                  1) Keep TV on then press: Mute + 1 + 1 + 9 + Enter (Its the button in the middle of the Left/Right/Down/Up arrows and may be labeled as OK or Select as well.

                  2) Power Off TV then press: Info + Settings + Mute + Power

                  3) Power Off TV then press: Mute + 1 + 1 + 9 + Power

                  4) Power Off TV then press: Mute + 1 + 8 + 2 + Power

                  5) Power Off TV then press: Sleep + P.STD + Mute + Power

                  6) Power Off TV then press: P.STD + Menu + Sleep + Power

                  7) Power Off TV then press: Display/Info + P.STD + Mute + Power

                  8) Power Off TV then press: Display/Info + Menu + Mute + Power

                  Comment


                    #10
                    Re: Samsung UN39EH5003FXZA won't stay powered off

                    Originally posted by Hannibal_Hector View Post
                    @Diah, the factory reset from the diagnostic menu didn't do it. Haven't tried the service menu, and I need to figure out how to get in there. Hopefully, it doesn't require the tv to be in standby!

                    @nomoresonys, that eeprom is the popular one, and I think it stores the configuration of the device, like the resolution, size, types of boards, etc. Yes? I am very curious about the other eeprom next to it, the so-8 size 24512RP. What does it store? I do not find mention of that one anywhere, with respect to this model. I want to put the scope on it and see when the SoC accesses it. I also want to dump it and see if I can write to it. It does have 3.3V on pins 1 & 8, so its getting juice.
                    again your suspect correct,

                    IC901 SOP16 are the Master EEPROM, While SOP8 24512RP are Slave EEPROM, the master will write it with the action and the slave will act under Operation "Acknowledge bit (ACK)"
                    RP Write programmable, working according to the master (SDA) Data. its responsible for:

                    1- Start Condition ( Power On ) this working at you..

                    2- Stop Condition : Stop is identified by a rising edge of Serial Data (SDA) while Serial Clock (SCL) is stable and driven high. A Stop condition terminates communication between the device and the bus master. A Read instruction that is followed by NoAck can be followed by a Stop condition to force the device into the Standby mode. A Stop condition at the end of a Write instruction triggers the internal Write cycle (This Stop failed at you)

                    Again, Hard reset from SM. will erase this slave too.. a good chance to correct it. OR using CH314A to erase it
                    Last edited by Diah; 03-04-2021, 09:59 AM.

                    Comment


                      #11
                      Re: Samsung UN39EH5003FXZA won't stay powered off

                      Well I would follow Diah's advice...sounds like he knows what he's talking about, interesting thread, will be watching, hope you solve it.

                      Comment


                        #12
                        Re: Samsung UN39EH5003FXZA won't stay powered off

                        Originally posted by nomoresonys View Post
                        Well I would follow Diah's advice...sounds like he knows what he's talking about, interesting thread, will be watching, hope you solve it.
                        thanks for nice comments.. but still your advice a valuable one.

                        this Master you mentioned could be suspect too... as i wrote before ((A Read instruction that is followed by NoAck can be followed by a Stop condition to force the device into the Standby mode. A Stop condition at the end of a Write instruction triggers the internal Write cycle ))
                        if the master didn't write "NoAck" the salve will be blind. or too the Slave already blind that it didn't read "NoAck" to act with (ACK)

                        Comment


                          #13
                          Re: Samsung UN39EH5003FXZA won't stay powered off

                          Ok, I have updates and some new knowledge.

                          Regarding the reset, the only one I can do is the first one from @vinceroger69's list, because I cannot put the TV into standby. However, the first one is only the Hotel mode. Interestingly, even if I put the TV into Hotel mode ON, it forgets that too. LOL

                          @Diah, providing some nice low-level activity... So, I read the 24512RP EEPROM with a CH341A, saved it just in case, and wiped it clean. This didn't work at all, and I wasn't able to power ON the TV and it never entered standby. It did the same thing it has always done: The red LED does a real quick blink, followed by 6 long blinks. So I wrote back the data I had read, and I am back to square one: The quick blink, 6 long ones, powers on. Try to power off, the cycle repeats and never goes into standby.

                          The data that is on the EEPROM is at the very least needed to power on, and from the dump I recognize, all of the channels from the channel scan, the WELCOME TO OUR HOTEL string, the serial # of the TV, a date, and another set of digits that looks like another serial #. There is lots more, but its encoded and not legible.

                          Becaue the only other memory I can see is the larger EEPROM IC901 and the Samsung DRAM chip K4B1G1646G-BCK0, I am now very tempted to replace IC901. Any thoughts!?

                          Comment


                            #14
                            Re: Samsung UN39EH5003FXZA won't stay powered off

                            right now you have tested and there signs of corrupted IC901.
                            A- erase the slave EEPROM didnt help.
                            B- Cant save last state of channel scan and Operation mode.

                            so go forward to replace it. in case of:
                            1- you dont owned RT809 programmer to play with it
                            2-Your PSU starting low after disconnecting mainboards (some time defect Optocoupler switched PSU to High at start)

                            Comment


                              #15
                              Re: Samsung UN39EH5003FXZA won't stay powered off

                              I have the IC901 on order from Jimmy. Still, there is something nagging at me regarding the PSU in the face of @Diah's comment about it starting low.

                              On my original post, I note that the PSON line goes to 3.5V when he TV is on, and briefly drops to 0V when it goes OFF, and then jumps back to 3.5V.

                              However, if I disconnect the main board from the PSU, the LCD panel lights up and all of the voltages are present, including 3.3V on the PSON line. I am confused by this, since this doesn't appear to be how other PSU's behave. But, there is a pull-up resistor across the PSON and 5V lines on the PSU, that explains why there is 3.3V present. If I remove the PSON pin from the connector, so the main board never sees this 3.3V, the main board gives the steady red light, potentially signaling standby, and there is no other voltage on the PSU connector, other than the 3.3V on PSON. There is no voltage on the main board's PSON line at that time.

                              Is this normal, or is there something odd about that behavior? Might be chasing ghosts.

                              Continued thanks to all helping me with this!

                              Comment


                                #16
                                Re: Samsung UN39EH5003FXZA won't stay powered off

                                Yep, that lighting up of the backlights lets you know that they and the powerboard are ok.

                                Comment


                                  #17
                                  Re: Samsung UN39EH5003FXZA won't stay powered off

                                  Some power supply have PSON at 3.5V ish and is taken low when brought out of standby.
                                  Willing to help but I'm no expert.

                                  Comment


                                    #18
                                    Re: Samsung UN39EH5003FXZA won't stay powered off

                                    Originally posted by Hannibal_Hector View Post
                                    If I remove the PSON pin from the connector, so the main board never sees this 3.3V, the main board gives the steady red light, potentially signaling standby, and there is no other voltage on the PSU connector,
                                    this is how it should. so IC901 the main suspect.

                                    but what you did above from test by blocking PSON brought to my mind idea that i never did before.. so its theory ..
                                    we do know the mainboards when it blocking PSON stay as red LED steady STB. and at this state it still can receive IR signal.. so how about if you try..
                                    send with the RC the service menu sequences following it by rmove the blocking of the PSON... can the set start with service menu LOL...

                                    Comment


                                      #19
                                      Re: Samsung UN39EH5003FXZA won't stay powered off

                                      Cool. Thank you for confirming this as normal behavior by the PSU. I hope replacing IC901 fixes it at this point, but who knows? I have had a lot of fun through all this either way.

                                      @Diah, good theory, but it didn't work, LOL. The problem is that the PSU never gets power_on signal, so there is no way it could show anything. Also, while the red light is ON, it doesn't flicker when sending it IR, so I am not entirely sure the SoC is really 'alive' enough in this state. It might be stuck in a loop, waiting for the PSU signal to show up.

                                      I have been tempted to get the interface that would let me connect a PC to the Service Port, but I think that if it gave any decent diagnostics, it would be easier to find information on this, and there is little talk of that port.

                                      Stay tuned!

                                      Comment


                                        #20
                                        Re: Samsung UN39EH5003FXZA won't stay powered off

                                        And, I'm back... Received the new IC901, swapped it out, and lo-and-behold... The same fault! (I also did try the only reset I have access to, which says 'factory'.)

                                        It is doing *exactly* the same thing with the new EEPROM.

                                        I don't see any other non-volatile memory devices on the board, so I am left with some logic issue on the PSON line or a bad SoC. Given how literally everything else is working perfectly, I am not inclined to fault the SoC and strongly suspect some transistor or passive not allowing the SoC to sleep.

                                        Any thoughts? Anyone have even a similar schematic for this mainboard?

                                        Comment

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