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Panasonic TC-P42C2 - No HDMI

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    Panasonic TC-P42C2 - No HDMI

    This one is a litte strange, after a power outage it came back on and the composite video inputs work but the HDMI ports do not. I've already done a factory reset.

    Does anyone have any advice before I go looking for a TNPH0831 board?

    (I've heard these are scarcer than unicorns)

    JayArr

    #2
    Re: Panasonic TC-P42C2 - No HDMI

    leave it unplugged from the wall for a "while" along with disconnected from all hdmi cabling. Sometimes hdmi stuff can get "confused".... of course, if your power "event" caused some powering issue, hdmi is very susceptible to voltage issues as there is some components in the hdmi subsystem that use 5v to do some "work". IF so, you are likely needing to look at the ic associated with hdmi signals.

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      #3
      Re: Panasonic TC-P42C2 - No HDMI

      Thanks Budwich but it's been unplugged for a week already.

      I tested the lines from the power supply to the main board and all the 15V and 5V voltages are there so I think you're right. I'll have to test all the little regulator ICs on the A board.

      Comment


        #4
        Re: Panasonic TC-P42C2 - No HDMI

        lastly, you tried more than hdmi device... perhaps if only one, that device had a problem with the power... maybe.

        Comment


          #5
          Re: Panasonic TC-P42C2 - No HDMI

          Hi Budwich

          Only two HDMI ports on this model and neither one works.

          I'm going to have to spend an hour with the service manual and my meter looking for a missing voltage line.

          Comment


            #6
            Re: Panasonic TC-P42C2 - No HDMI

            I think you misunderstood what I asked... I was referring to the source... dvd player or otherwise as opposed to the ports... try more than one device.

            Further, does the set acknowledge there is a connection when the plug is inserted or nothing... ie. something like no signal... check connection?
            Last edited by budwich; 02-14-2019, 12:08 AM.

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              #7
              Re: Panasonic TC-P42C2 - No HDMI

              Hi Budwich

              OK, I understand now. The source works, it's an old Boxee Box and it produces a signal on the set on the other bench, this is also the fault the customer brought it in for.

              The set doesn't acknowledge anything at all.

              The same IC (8001 - NILE TCON) processes both the HDMI and the composite video signals. Since comp vid works and I have rarely seen "part" of a processor IC fail I'm leaning toward some voltage regulator failure. There looks to be three regulator circuits in the top right corner of the board and one just above IC9300. I'll have to find some time to check them all out to see if a voltage is missing.

              Man is the writing on these boards ever TINY! My 55 year old eyes are having a tough time. I've got a microscope to solder with if/when I find something but it's no good on a live chassis.

              JayArr

              Comment


                #8
                Re: Panasonic TC-P42C2 - No HDMI

                Yes, you will want to test the regulators. There are several to consider:

                IC9801 (15V -> 5V),
                IC9803 (15V -> 3.3V),
                IC9800 (15V -> 1.2V),

                IC5606 (15V -> 1.2V),
                IC5608 (15V -> 1.8V),
                IC5610 (15V -> 5V)

                IC5605 (5V -> 3.3V),
                IC5607 (5V -> 3.3V), <<<<<<<<HDMI
                IC5609 (5V -> 3.3V),
                IC5613 (5V -> 3.3V), SD Card
                Check pin 18 of HDMI ports 1 and 2 for 5V.

                Check Q4501 (HDMI 2)
                Check Q4502 (HDMI 1)

                I attached a service schematic for TC-P42U2, but uses TNPH0831 board and may be useful here. I don't have a schematic for TC-P42S2. Page 55 is related to the HDMI ports. Lots of lines to check for voltages or shorts.

                See if anything doesn't make sense with the manual.
                Attached Files

                Comment


                  #9
                  Re: Panasonic TC-P42C2 - No HDMI

                  Originally posted by JayArr_BC View Post
                  Looking to buy EMP-20 modules/programmer JayArr
                  I could not reply to you in the looking to buy thread

                  You may find some information here: https://forums.arcade-museum.com/arc.../t-405409.html
                  Last edited by R_J; 02-26-2019, 11:20 AM.

                  Comment


                    #10
                    Re: Panasonic TC-P42C2 - No HDMI

                    ...

                    Comment


                      #11
                      Re: Panasonic TC-P42C2 - No HDMI

                      Thanks Unspun01, I'm sure the TP-42C2 is just the Canadian version of the USA TP-42U2 so the manual should be identical. I'll try to work through all these regulators tonight and see if I can find one that has quit.

                      Also: Thanks R-J, I'm looking into that site for my programmer.

                      Comment


                        #12
                        Re: Panasonic TC-P42C2 - No HDMI

                        OK, here's an update, I checked all of the regulator circuits that Unspun01 listed a couple of posts back, everything was OK.

                        Then I started to trace out 5V on pin 18, this is a reception point not a supply so it's only there when you plug in a live HDMI cable. That was also working.

                        I started following that 5V back towards the Q4501/2 that was suggested and I noticed that on one port the SCL line had only 25 ohms to gnd. I removed some components and traced it back and the problem is inside the TCon IC itself.

                        It's a guess but when the power surge hit there was some differential between the HDMI device and the TV and it blew out the IC, I'll also guess that once one HDMI port stops working they all stop, either they were all damaged or it's stuck in a loop trying to detect what's there with a short on the line. At any rate this board isn't going to run HDMI anymore.

                        So... assuming... that I don't want to everu receive broadcast TV or cable again can I buy any old TNPH0831 board and program it for my 42" chassis and repair this unit as an HDMI only TV?

                        JayArr

                        Comment


                          #13
                          Re: Panasonic TC-P42C2 - No HDMI

                          JayArr:

                          If you decide to buy a different TNPH0831 board, be careful to get exactly the same connectors and locations. EXACTLY. The TNPH0831 board can be populated with many different connectors and locations so it needs to be the same. Specifically, the VGA port may or may not be populated. Most important is the 3 ribbon cable connectors on the left side of the board. I have a few different versions of this board, and they are not interchangeable because of the different ribbon cable connectors for different panels.

                          The TC-P42C2 is a 720p TV with 1024x768 pixel resolution so you would be able to use a 50" 720p panel board. 1080p boards would not work because the panel connectors are different..

                          ----------

                          Back to troubleshooting (and with reference to page 55 of that manual I shared):

                          Can you please tell me if you removed or tested D4510/D4511 on HDMI 1 or D4503/D4507 on HDMI circuits? These appear to be TVSS devices (transient voltage surge suppressor), and may well short during an incident to prevent further damage. These are connected directly to SCL and SDA lines and may be the short you are measuring.

                          It is difficult to explain where D4503/D4507 are. They are located topside (not labeled) but are adjacent to HDMI connector JK4501.

                          D4510/D4511 are located bottom side (not labeled) near test point TP4505.

                          If you search for the text D4503 or D4507 or D4510 or D4511 in the PDF, it will point you to the exact location on page 76 and 77.

                          These parts should not normally conduct. Therefore if one or more measure low resistance or short, they could be the issue. Remove it and re-test.

                          It may fix your problem. TV can operate without them (since they are only protective devices) but you may not be protected again if they are not reinstalled.

                          Also, if those are removed and test good, then your HDMI IC may be pooched anyway.

                          If all else fails, you can get an HDMI to Composite or HDMI to component converter device for less than the cost of a replacement board.

                          Comment


                            #14
                            Re: Panasonic TC-P42C2 - No HDMI

                            Thanks Unspun01

                            I've removed L4512, the 47K resistor and the TVSS from the board and there is no short on TP4505 but there is still 25 ohms to gnd on the scl line to the IC so I'm pretty sure the problem is in the IC. The scl line on the other port does not have this low reading.

                            There is an old trick of applying a DC voltage to 'clear' a short and I may try it after I've replaced the board (once I have nothing to lose) if I can blow out the short on this port maybe the other one will start working, it's risky, I could blow the whole IC and lose everything.

                            I've found a replacement board specifically for the 42C2 and it's on order but this customer has another identical TV with the identical problem caused at the exact same time (power surge after blackout) so I'm going to need another one and they are rare. I like your idea of trying the 50C2, there is one on eBay.

                            Comment


                              #15
                              Re: Panasonic TC-P42C2 - No HDMI

                              Originally posted by JayArr_BC View Post
                              Thanks Unspun01

                              I've removed L4512, the 47K resistor and the TVSS from the board and there is no short on TP4505 but there is still 25 ohms to gnd on the scl line to the IC so I'm pretty sure the problem is in the IC. The scl line on the other port does not have this low reading.
                              The individual TVSS chips (D4503, D4507, D4510, D4511) are small, individual components that look much like a smt ferrite bead. Unless you have removed each one, you can't be sure...

                              However, if you remove L4511, L4512 (for HDMI 1), and L4504, L4505 (for HDMI 2) to isolate from the SCL/SDA bus, then you do not need to test the individual TVSS chips (D4503, D4507, D4510, D4511) since they will be isolated from IC8001.

                              With the 4 SCL/SDA inductors removed, no short on TP4504/TP4505 (HDMI 1) or TP4501/TP4502 (HDMI 2) is good sign for the HDMI ports themselves, but a short on SCL is still bad sign for IC8001.

                              I agree, from your description, it is most likely Tconn IC8001 as you found.

                              That is a painful chip to try and replace. I've successfully replaced HDMI switching ICs on other older Panasonic TVs and other brands, but usually they are QFP chips with exposed pins that can be soldered by hot air or re-touched by fine-tip solder iron... This BGA is difficult,and therefore would be easier to find same TNPH0831 board style and transfer over the programmed onboard flash chips, etc.

                              I'll check my inventory of boards to see if I have anything for you.

                              In the mean time, follow the same method of troubleshooting on your customer's other damaged TV. It's possible the problem presents the same way, but his IC8001 could still be good, and only need replacement of some of the small smt parts from this TNPH0831 board that you and I suspect is not worth fixing.
                              Last edited by Unspun01; 03-13-2019, 02:32 PM.

                              Comment


                                #16
                                Re: Panasonic TC-P42C2 - No HDMI

                                Hi Unspun01

                                I replaced BGA ICs for years on motherboards and was pretty good at it but when boards get below $100 the profit is too small and I sold my IR machine and all of my re-balling stencils and gear last year. I still have a 180X microscope that I do all of my tiny SM soldering under so removing individual tiny sm devices is not a problem.

                                I see 5 programmed ICs on this board so now it will be a matter of figuring out which controls what.

                                IC8004 - EEprom - MCU
                                IC8502 - Flash - T-con
                                IC8503 - EEprom - IIC2
                                IC9001 - EEprom - panel micom
                                IC9304 - flash - Plasma processor.

                                If I can get another board produced for the 720p C2 series (they made 42, 46 and 50" models) I can do some experimenting to see what, if anything, needs to be re-wriiten to change it to a 42". I'm assuming that all of the programmed ICs on this board are intact.

                                I'll check my inventory of boards to see if I have anything for you.

                                In the mean time, follow the same method of troubleshooting on your customer's other damaged TV. It's possible the problem presents the same way, but his IC8001 could still be good, and only need replacement of some of the small smt parts from this TNPH0831 board that you and I suspect is not worth fixing.
                                I'd appreciate that, my hope is that the TVSS on the other unit shorted and protected the IC8001, that is exactly what it was put there to do, unfortunately I have to finish repairing this one before I can get my hands on the other one.

                                Comment


                                  #17
                                  Re: Panasonic TC-P42C2 - No HDMI

                                  Some of those EEPROM ICs handle low-level stuff and are probably the same across all models. You probably only need to change one or two, not all of them.

                                  I had a 1X blink code on a Panasonic A-board (TNPH0831) of my TC-50PX24 due to a bad IC9304. I only had to swap the one chip to repair the TV.

                                  See thread:
                                  www.badcaps.net/forum/showthread.php?p=359014

                                  Comment

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