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Soldering a DVI connector on a VGA-only motherboard.

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    Soldering a DVI connector on a VGA-only motherboard.

    Hello. How important are the SMDs right before the DVI connector? Can it work without them, given that, if necessary, I could just solder the contacts for continuity. I know it's raw and reckless, but can it output DVI signals without them? I want to add a DVI port to a VGA only motherboard. ASRock H81M-VG4 and using boardview for H81M-DG4. Same H81M-*G4 board. I have option in BIOS for IGP multi monitor and my pockets have holes.

    Any insights appreciated.

    #2
    Re: Soldering a DVI connector on a VGA-only motherboard.

    dvi has 2 modes, digital, and analog
    the motherboard may not support both, and you will need the smd parts are they fitted or missing?

    Comment


      #3
      Re: Soldering a DVI connector on a VGA-only motherboard.

      I have a VGA connector only, so I am interested in the digital part of the DVI. There are no smd parts fitted for the DVI connector and I do understand that they should be there if I want to use it. What is the importance of them and could it work without them? was the main question. I could bridge the contacts with solder. Actually I am not even going to use a DVI connector, I only need the rails. I have the pinouts for the DVI, board schematics and boardview for all 3 ASRock H81M-*G4 motherboards. Again: how important are the smds and will it work without them?

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        #4
        Re: Soldering a DVI connector on a VGA-only motherboard.

        you need the parts.
        you should be able to work out what they are from a datasheet of the gfx chip - they often have example schematics.
        you can also get the dvi pinout and compare it to the board to see if it's got tracks for digital, analog or both.
        because the signals use seperate pins.

        or find out what part number that board has when the connector is fitted - and download it's manual.

        Comment


          #5
          Re: Soldering a DVI connector on a VGA-only motherboard.

          Thanks for the reply. I really want an open minded approach, meaning that even though not having enough experience, I wish to bypass the dvi connector and just use some of the contacts, for the digital signal. No audio needed, as I use the green jack. Again... I know it's raw or reckless, or you name it! So if solder the wires on the contacts before the SMDs, would I get image on the monitor? Imagine a digital DVI monitor with the cable soldered on the PC motherboard. Finding the right contacts is not a problem. Bypassing the SMDs and DVI connector is what I want.

          Edit: What would break if I do this anyway?
          Last edited by freeman0711; 10-01-2020, 05:48 AM.

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            #6
            Re: Soldering a DVI connector on a VGA-only motherboard.

            there is no audio on dvi - your confusing it with hdmi that has no analog video but does have audio
            and no, you cant bypass the smd parts, they do stuff.

            if you want to fit the parts inc the socket then go for it,
            but bypassing the connector risks ripping tracks off and could damage the gfx chip

            Comment


              #7
              Re: Soldering a DVI connector on a VGA-only motherboard.

              Even though there may be traces on the DVI portion of the connector and even if the chipset supports it, the DVI interface on the controller may have been disabled under customization of the BIOS.
              My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

              Comment


                #8
                Re: Soldering a DVI connector on a VGA-only motherboard.

                Originally posted by stj View Post
                dvi has 2 modes, digital, and analog
                the motherboard may not support both, and you will need the smd parts are they fitted or missing?
                It does indeed support audio. I had a Gigabyte H81M-S2PV, which had VGA and DVI. DVI was both digital and analog (different rails, I know) and the TV that was connected to, had also audio if I used a DVI/HDMI adapter. So from this I understand that digital dvi signals are same as HDMI, at least on the TV/monitor side. On the motherboard side is a different output, with it's own framebuffer, pipe and stuff.

                Comment


                  #9
                  Re: Soldering a DVI connector on a VGA-only motherboard.

                  Originally posted by japlytic View Post
                  Even though there may be traces on the DVI portion of the connector and even if the chipset supports it, the DVI interface on the controller may have been disabled under customization of the BIOS.
                  That is part of the journey. I the option of IGP Multi-Monitor.

                  Comment


                    #10
                    Re: Soldering a DVI connector on a VGA-only motherboard.

                    from the board layout, it's digital only.
                    and dvi does not support audio
                    https://pinouts.ru/Video/dvi_pinout.shtml

                    Comment


                      #11
                      Re: Soldering a DVI connector on a VGA-only motherboard.

                      Originally posted by stj View Post
                      from the board layout, it's digital only.
                      and dvi does not support audio
                      https://pinouts.ru/Video/dvi_pinout.shtml
                      I think you're right, the gigabyte board supported only digital dvi, but I got audio working oob in windows through that DVI connector. I don't have that board anymore anyway. What would happen if I solder the wires on the board, on the digital DVI rails? I might do it anyway, so please, I just need some insights, posting back results. Let's have some fun with my board.

                      Comment


                        #12
                        Re: Soldering a DVI connector on a VGA-only motherboard.

                        Originally posted by freeman0711 View Post
                        How important are the SMDs right before the DVI connector? Can it work without them, given that, if necessary, I could just solder the contacts for continuity. I know it's raw and reckless, but can it output DVI signals without them?
                        It's been a while since I did an in-depth analysis of DVI-D connector SMDs... but generally speaking, you shouldn't by-pass any SMD capacitors, especially if they go between signal and ground (there may be a few for noise reduction on the digital lines.) I also don't remember if there were any pull-up/down resistors, but if there are (use your motherboard schematics), you can't bypass those either. However, you could try hooking the digital DVI-D lines directly to the connector output to see if you will get an image. No guarantee, though.

                        A lot of DVI connectors also have SMD Zener/clamp diodes for ESD protection. Zap any data pins on a board that doesn't have those (and I've seen this on really cheap LCD monitors), and you may end up with a dead GPU.

                        So yeah, you can try it, but I'm not sure if it would work and you should also pay close attention to limit ESD when connecting/disconnecting the DVI cable (touch device/PC ground and cable ground so they are at the same potential before connecting together.)

                        Originally posted by freeman0711 View Post
                        It does indeed support audio. I had a Gigabyte H81M-S2PV, which had VGA and DVI. DVI was both digital and analog (different rails, I know) and the TV that was connected to, had also audio if I used a DVI/HDMI adapter. So from this I understand that digital dvi signals are same as HDMI, at least on the TV/monitor side. On the motherboard side is a different output, with it's own framebuffer, pipe and stuff.
                        Correct.
                        I have an MSI MS-7778 board with VGA (D-sub) and DVI-D only. No HDMI connector, unlike most A75 board (socket FM2+ APU with graphics.) I too have successfully used a DVI-D to HDMI cable to pass audio through to a TV.

                        So yes, DVI-D can carry audio, if the output device supports it.
                        Last edited by momaka; 10-02-2020, 07:39 PM.

                        Comment


                          #13
                          Re: Soldering a DVI connector on a VGA-only motherboard.

                          Originally posted by momaka View Post
                          It's been a while since I did an in-depth analysis of DVI-D connector SMDs... but generally speaking, you shouldn't by-pass any SMD capacitors, especially if they go between signal and ground (there may be a few for noise reduction on the digital lines.) I also don't remember if there were any pull-up/down resistors, but if there are (use your motherboard schematics), you can't bypass those either. However, you could try hooking the digital DVI-D lines directly to the connector output to see if you will get an image. No guarantee, though.

                          A lot of DVI connectors also have SMD Zener/clamp diodes for ESD protection. Zap any data pins on a board that doesn't have those (and I've seen this on really cheap LCD monitors), and you may end up with a dead GPU.

                          So yeah, you can try it, but I'm not sure if it would work and you should also pay close attention to limit ESD when connecting/disconnecting the DVI cable (touch device/PC ground and cable ground so they are at the same potential before connecting together.)


                          Correct.
                          I have an MSI MS-7778 board with VGA (D-sub) and DVI-D only. No HDMI connector, unlike most A75 board (socket FM2+ APU with graphics.) I too have successfully used a DVI-D to HDMI cable to pass audio through to a TV.

                          So yes, DVI-D can carry audio, if the output device supports it.
                          Thank you for the reply.
                          So I have one thing that I haven't thought about: make sure ground is available at the socket.
                          I will post back results in a few days.

                          If it doesn't show anything in the BIOS POST, I will go deeper into the schematics of the DVI model of the board and see what parts I have to order.

                          Cheers!

                          Comment


                            #14
                            Re: Soldering a DVI connector on a VGA-only motherboard.

                            you will probably not get an image because the board needs to detect the monitor and read it's eeprom through the edid lines to detect the correct resolution.

                            Comment


                              #15
                              Re: Soldering a DVI connector on a VGA-only motherboard.

                              Originally posted by stj View Post
                              you will probably not get an image because the board needs to detect the monitor and read it's eeprom through the edid lines to detect the correct resolution.
                              You are right. Also, I have found that it needs 2x transistors, caps and resistors galore, a ferrite. I am ordering the parts together with a DVI connector. Thank you all for the heads-up. I will post back when I finish. It's going to take a while for some personal reasons.

                              Cheers!

                              Comment


                                #16
                                Re: Soldering a DVI connector on a VGA-only motherboard.

                                I have finally ordered the parts. I ordered from aliexpress and I don't know when they will be here, but the moment they arrive I will post back, maybe just to bump the thread so that if anyone else is following this thread will be notified. I hope to mark the thread as solved. Thank you all.

                                Comment


                                  #17
                                  Re: Soldering a DVI connector on a VGA-only motherboard.

                                  Will be interesting to see the results.

                                  Also, threads on BCN stay open indefinitely so that anyone who may have a question regarding the topic can read and post in your thread. As such, there is no resolved/unresolved option. Just post back here when you've tried the mod.

                                  Comment


                                    #18
                                    Re: Soldering a DVI connector on a VGA-only motherboard.

                                    Bump.
                                    I have received the components yesterday. Today is the day!

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