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Hellfire Repair Log

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  • Hellfire Repair Log

    Symptom: all main sprites only being display in the ?middle? column of the display (about 4 inches wide on a 14? monitor)
    Cure: Corroded track leading from pin 11 of the LS163 at 2B that goes to pin 13 of the LS157?s at locations 5J and 7J. Track repaired, fault fixed.

  • #2
    I have just made myself a test rig, and am thinking of tackling a non working Toaplan Hellfire PCB I have. I have chosen this PCB specially because it has a few resistors & caps missing, track damage, and looks to have been bashed around. The reason I choose this is that although it may be difficult to fix, by fixing the obvious physical damage type faults I can see what difference it makes as I go along.

    Firstly I want a Hellfire schematic, but I can't find one! Does anybody have one/ know where one is? I have searched a whole bunch of sites commonly referred to on AA with no luck.

    Can anybody help?

    Comment


    • #3
      Probably there isnt one, very few boards have schematics available online, thankfully they are rarely needed to fix a board, unless the damage is so bad you cant see where things once went.
      Sic transit gloria Atari!

      Comment


      • #4
        Ahh well, I might need to refer to someone who has a working PCB to work out what values of resistors/ capacitors are missing. It is wierd, they have been either snapped off or cut off deliberately. The board is a bit of a mess, however I just want to have a play and learn as I go. Tonight I might list the locations of the missing bits for reference.

        Comment


        • #5
          manual has a list of parts inside it

          http://arcarc.xmission.com/PDF_Arcad...nd_Schematics/

          [ ] Helifire.pdf 14-Jul-2002 09:46 1.6M
          you can always expect change in life..except from vending machines

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          • #6
            Ah yeh, missing bits, doh!

            The parts list should help, most caps outside the amp section are smoothing caps and not overly critical. Ceramic caps near TTLs are almost always 104K's
            Sic transit gloria Atari!

            Comment


            • #7
              Thanks Narf but I am after Hellfire (not Helifire).

              I thought I found manuals/ schematics many times over but unfortunatley they were all for the latter.

              Comment


              • #8
                bugga
                you can always expect change in life..except from vending machines

                Comment


                • #9
                  Well I have figured out what the missing values are, as the same ones are all over the board. They look like little resistors, but they are capacitors. The markings are Red, Red, Orange, White so I guess that makes them 2.2uF. There are in total 5 missing. Also when the board was powered up, by touching the board ever so slightly different patterns of junk came up on the screen. I can already see some track that are potentially broken, some chips with squash damage and heavy scratches, and at least one socketed chip that looks like the legs are all over the place. Plenty to do straight up just on the physical side here./

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                  • #10
                    I also have a damaged Hellfire board. This is one of my favourite games. Let me know if theres anything you'd like me to have a look at for you.

                    I have never in my life heard of capacitors marked with colour codes. Are you sure thats what they are?

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                    • #11
                      I'll remove one and check to make sure, but on the PCB they have the non-polarised capacitor symbol underneath, and they are in places where there are normally capcitors. Here is a link to stuff about capacitor colour codes, scroll down to figure 3-23 http://www.tpub.com/neets/book2/3g.htm

                      They look like resistors, but everything else points to them being capacitors. I'll know for sure when I take one out.

                      Comment


                      • #12
                        They are capacitors, caps with colour codes are very common on early 90s boards, non-bootlegs mainly, they look like little resistors, about half the length and usually yellow or white with colour bands. Usually one per TTL chip where you would expect ceramic caps to be on older boards or bootlegs.

                        When a TTL chip switches its output it takes more current during the switch than when the gate is either high of low, this leads to a tiny dip in voltage at the chip, the caps are there to smooth out these ripples, 74LS is much lower power than original 74 series TTL so its less of an issue, but the caps are still there as its good design, leads to a stable board. If a few are missing it is not going to stop a board in its tracks, they just are insurance against noisy power supplies which may lead to unstable boards. The only time a cap is likely to halt a board is if its part of the reset delay system, ie a cap feeding a not gate on something like a 74LS04 which then connects to the Reset line on the cpu.

                        I wouldnt take it off if I were you, they are very fragile, it is likely to fall apart due to the heat and stress of removal.
                        Sic transit gloria Atari!

                        Comment


                        • #13
                          Cool thanks Womble

                          Comment


                          • #14
                            When firing up the board you just get junk, but can barely make out the font of the high score table etc. One of the roms looks bad, legs bent everywhere. Pulled rom 04 off the board. 2 legs had ends snapped off, 2 legs bent under, all legs bent a bit sideways. Fired board up without that rom in. Can see more of the game now, jailbars all over screen, but game coins up, and sounds/ music are perfect! I nearly soiled myself hearing the music.
                            Carefully bent leg pins all back to straight positions, and repaired the legs that had broken. Dropped the rom back in the board. Now the jailbars are gone. Most sprites look perfect, some background issues, some bits don't line up properly. Also when attract screen playing, there is some random corruption on the screen, can vaguely make out some 0's in it in columns. Also slightly tapping the table the PCB is on causes colours to go missing (red, green or blue). A few more taps they come back. Very sensitive to this.
                            Last edited by Roxbury; 3rd February 2010, 07:27 AM.

                            Comment


                            • #15
                              Sounds like you are almost there, check for other bad roms, oxidized sockets and any pins bent and touching on the solder side of the board. I have a rom pin straightener, a few bucks from jaycar, drop in a chip and squeeze hard, works very well.
                              Sic transit gloria Atari!

                              Comment

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