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    Frogger Picture Mosaic

    I have a Frogger cabinet I am restoring but the picture is all mosiac.

    The system powers on, sound works, coin(s) insert works, selecting P1/P2 works as does game sound and controls. The game is even playable.... sort of

    In the picture (on the left) below you can see the game screen and the Frog in the middle. The frog/character displays OK, has the propper colouring and you can even see (a representation of) the cars/trucks scrolling across the screen in their respective lanes.

    I have cleaned the board, reseated removable chips, checked the board for but cant see any obvious damage and checked/adjusted the voltages (+5V was initially about 4.2V).

    Any pointers on where to look / how to resolve this issue?

    #2
    It really depends if you have the basic diagnostic tools required to repair the board, sounds like you've covered the basics. Could be a bad ram or buffer its hard to say but at least the game is running!
    I'd start by looking at old repair logs.

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      #3
      Could be RAM, ROM or logic issues I'm afraid.
      Sic transit gloria Atari!

      Comment


        #4
        Re-flow the RAM & ROM legs, possible a dry joint.

        Comment


          #5
          Originally posted by Gemini2544 View Post
          Re-flow the RAM & ROM legs, possible a dry joint.
          I don't advise doing that, the chances it is a dry joint are astronomically small, and the chance you will create, or introduce a bridge is very high. Can you post a photo of the PCB? Frogger has a tonne of variations out there so google won't necessarily help.
          Sic transit gloria Atari!

          Comment


            #6
            Originally posted by Womble View Post

            I don't advise doing that, the chances it is a dry joint are astronomically small, and the chance you will create, or introduce a bridge is very high.
            I only said "Possible dry joint". So any additional damage done by the O.P would be his doing.

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              #7
              Thanks guys - So pretty much - "check most of the board"

              I have a multimeter, soldering iron, basic skills.... learning fast. This is my first jump into Arcade tech (a lifelong dream).
              I dont have a logic probe or oscilascope... yet! but may end up with more diagnostic "toys" by the end of this.

              I have also noticed that the 36 pin harness is dodgy, The slightest touch or movement to the harness cables at the connector causes dramatic/strange changes to the display. Also the 1P/2P buttons randomly stop working (also at the harness connector).

              So a few issues to sort outl

              I will hold fire on reflowing the ROM and RAM. The logic chips will be a nightmare to sort through due to the number of them and the lack of specific tools.

              Comment


                #8
                let me know if the photos need to be better quality

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                  #9
                  Quality is great, but unfortunately there's nothing that sticks out as a likely candidate, Fujitsu 74xxx chips from this era aren't the problem they are on later boards as I guess they changed the manufacturing process. If you had any daughter-boards I'd suspect the contacts as they are usually just rammed in to sockets which is a very bad design and they tend to be in the gfx section of pcbs.

                  Your fault will likely be on the larger of the two boards, as the game is running and controllable the smaller CPU board is probably fine.

                  You'd need a logic probe or a scope to progress further. Shotgunning the repair is pretty hit and miss when you work blind, plus it involves a lot of desoldering which is risky without the correct tools. You could track down some replacement DRAM ICs for the bank of 4 and do a swap, but a scope would show you whether the ones on the board are being driven correctly and whether their output is sane.

                  I can't tell which is pin 36, but I'm guessing its on the underside, so it is probably the -5v. On older boards that's often used by the video generation section so an interruption will cause craziness. Then again Frogger had a range on pinouts so it's only a guess.

                  If you were in Vic and we weren't in lockdown I'd suggest bringing it over for a board repair lesson.
                  Sic transit gloria Atari!

                  Comment


                    #10
                    Where did you check the voltage ?
                    When I first start any new to me machine, I first disconnect the game board, then check voltage at the power supply, then plug the board back in, then check the voltage on the board, then adjust if needed.

                    Another thing I do when re-seating chips is check that the socket is in good condition and make sure you didn't bend any legs while re-seating.


                    If you think you'll be working on more PCB's, its worth getting hold of a ROM reader / writer...
                    Checking the ROM's is the next thing I'd normally do, just to rule them out.
                    sigpicArcade Parts: www.vadership.com

                    Comment


                      #11
                      Yep - if you are going to be doing more than one it pays to invest, it is never harder than on day one when you only have basic tools.
                      Sic transit gloria Atari!

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                        #12
                        I'd be sorting out that connector first though, If things are going weird when you touch it suggests loose/bad connections.

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                          #13
                          Harness sorted out, simply pulling the pins, bending the connectors out a bit and giving them a quick rub with some 600 grit sandpaper worked a treat. It is now stiff and resolved the glitches.

                          From a previous reply re voltage checking, I checked and adjusted the voltage +5, -5 and 12 at the PSU with the PCB disconnected. They were all a bit low. I like that this old PSU that has an adjustment pot for each of the three voltages insividually. Then I reconnected the PCB and tested at the connector fingerboard. Small voltage drop through the harness (4.97v). Then I tested across some of the chips. Voltage on the soundboard was roughly 4.96. But on the main board there was further drop, down to 4.87. I readjusted the voltage back up to 4.95 on the main board as I didn't think it wise to drive too much voltage through the sound board (now at 5.03).

                          Anyway, that is all a bit academic as the problem is beyond my current level of skills or tools. I was kind of hoping one of you guys had seen this before and just said "oh yeah, just replace IC82 or the RAM chips".

                          So for now it will go into my 'sometime down the track' queue. I have ordered a Jamma harness (from Vader), already have a 60-in-1 and will just get the table up and running for now, so I can get on with reliving my youth through 1942, Time Pilot and Bombjack. I had ordered a stern/konami to Jamma adapter from the US, so that I didn't have to replace the harness but thanks to Corona, that will probably not get here till Christmas.

                          I'm thinking of making my own repro Hankin table, as I really wanted the full length CP version and the 19/20" monitor. If I do end up with the two tables, I may revisit the Frogger board to return this cab to its origional state or find someone willing to part with a working Ghosts'n'Goblins PCB.

                          Anyway, thanks for the help and advice guys, much appreciated.

                          Comment


                            #14
                            20" Hankin table, like this style?

                            Click image for larger version

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                              #15
                              Yup Gemini, that is the style I am after. My Frogger cabinet is the older half sized centre CP Hankin style.

                              Although I did uncover that my cabinet origionally housed a Missile Commnad game. The CPs had the three small semicircular located Volcano button holes to the left and large trackball hole to the right. Someone had drilled a centre hole to add the joystick and glued a panel over the top of the origional.

                              I contemplated taking this cabinet back to its Missile Command glory but that configuration would be too limiting (for a 60-in-1, Ghosts'n'Goblins, etc).

                              It is my ultimate goal to ressurrect the Frogger board eventually and make the cabinet origional(ish). I have just refurbed the cabinet and got it looking A+ again. Other than the internal paint, replacing the controls (original short shaft Sanwa Joysticks were DOA) and adding Fire/Jump buttons, the cabinet and wiring is completely origional.

                              I have the measurements from this cabinet and the plans for your style of Hankin, so I may repro one for my second cabinet with a 60-in-1 and updated electronics.

                              Which means I'll need a third cab for Ghosts'n'Goblins... then a fourth...
                              I guess thats how it all starts - that first cabinet and plans for the second!

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