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Last Action Hero from hell repair log

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  • Last Action Hero from hell repair log

    Hey guys,

    I finally got my LAH up and running after I pieced it together from MANY bits and pieces. I got the machine sans all boards, but complete playfield/cabinet was nice and cheap

    I decided to buy a heap of untested (we all know that that means!) boards and have a crack at fixing them myself. Here is my story

    I purchased a new DMD from Judgeboz (cheers Boz!) and a new Rottendog power supply form Mad Amusements (which arrived in a couple of weeks, thanks Mike).
    I knew that without a decent power supply and a good DMD, trouble shooting the rest was going to be a nightmare.

    MPU:

    I got a set of ROMs from thatpinballplace.com and bunged them into the MPU. The machine booted (with the coin door open) and I was able to see the ROM screen on the DMD controller, but then it went blank.

    After a bit of poking around, I saw that the data lines going from the MPU to the DMD controller were not doing much, so I suspected the 6821 PIA on the MPU at 8/9B.
    I touched it and it was HOT! Out came the PIA and in went a socket and a new one (Cheers Skybeaux) and things improved.... slightly!


    DMD Controller:

    When I got this board, the seller explained that the board would display the ROM check screen on boot and then continuously reset constantly flashing the boot screen. After fixing the PIA on the MPU, it did indeed do this.
    Now that the MPU was working, it was sending a reset signal to the DMD controller every 0.5 seconds.

    Not knowing how these work, I suspected that the DMD controller was working (given the ROM boot screen), but the MPU wasn't gettting what it needed and was resetting the DMD Controller. I also noticed a fair bit of corrosion on the right hand side of the board which is near the interface circuitry for the MPU.
    I started buzzing out the lines that go back and forth from the MPU to the DMD controller. There are 8 data lines, 4 status lines, a reset and a busy signal.
    After much swearing, I must have missed the busy line the first time because I finally found a broken trace on pin 5 of U20 back to the ribbon cable header! It was under the IC and totally invisible. I removed the IC and it looked ok, but my multimeter was saying otherwise.
    I fixed the track, added a socket and a new IC and voila! the DMD sprung to life! Woo-hoo!

    PPB board:

    At this stage, I was able to play a game and everything seemed to work, except the Ripper solenoid.
    Browsing the schematics showed that the Ripper is fired by a high power darlington transistor on the PPB (a.k.a. Popcorn Popper Board). I checked out the board and apparently someone had needed the diode D21 and resistor R19 for something else and decided to yoink them. Replacing them restored the Ripper!

    MPU (Again):

    After being able to play games, I noticed that even after I installed a remote battery pack, my scores and settings weren't being saved. The machine would also not boot without the coin door open, displaying "Open the door" on start up.
    Pinrepair stated that the diodes on the input of the battery pack could die so I checked them. Nope, they were ok. I checked battery voltage right on the pin of the RAM. It was ok!
    What the hell? Bad RAM? I pulled the RAM from its socket and put it back and all of a sudden - it worked! Nice one.

    Audio board:

    Up until now, everything was working except sound. The two sound boards I'd collected both had various bits missing so I managed to snag enough ICs from one to complete the other. (Big thanks to Humpalot for one of those boards!)

    On startup, I would get the "I'll be back" from Arnie followed by a continuous loop of the background music it starts up with (which didn't sound right when compared the the Pinmame version), but nothing else. Not even in speaker test mode.
    Poking around with the oscilloscope, I noticed that some of the lines on the data bus were only switching between 0-2V - strange. The RAM I'd used on this board had come from the donor board and I'd desoldered it. It was a 6116 24pin DIP but the board can also accept a 28 pin 6264 RAM. I found one in my stash and plugged it in. I also had to remove jumper W5 and install jumper W4 to get it to work.

    Hey presto - sound!!!!

    Through the sound test, I noticed that the left speaker wasn't working but the channel was. They are mixed together for the centre speaker and that was working.

    A Quick probe of the speaker revealed an open speaker coil so I replaced them both.

    Playfield stuff:

    When I got the game, the gearbox in the crane was toast, so I purchased a new one from Bay Area Amusements. That didn't go so well, but there's a separate thread for that HERE

    I'm nearly there, I just need a few playfield adjustments and it'll be good.

    I'm really liking this game - there's so much to do!

  • #2
    Well done on the repairs and getting the game to the stage you have. You certainly haven't had it easy getting in going. Good news that you've repaired some boards and now have some spares. In the process of fixing up a LAH for someone, haven't started on the boards though it did work before I pulled it all apart. Hopefully it still will when I put it all back together.

    Comment


    • #3
      Another under rated DE game ...... " get the red eye"

      Man thats alot of fixin.
      The Artist Formally Known As #1

      Comment


      • #4
        By the sounds of it you got really lucky with your untested boards,well done on the fault finding and repairs.
        Wanted Taito or universal cabinet any condition dead or alive.

        Comment


        • #5
          Hi,
          Your log was very helpful with many areas as I have the same one. But mine stopped working partially. I did a diagnostics test (coil/flash). 11 of 29 are not working. This causes no ball release. Everything else seems to work. But machine is now unplayable. Coils and Flash not working found...

          Coil: lockout
          Flash: 4-big rgt mars
          Coil: ball release
          Flash: 1-ins 3-plfd
          Coil: crane lock
          Flash: 2-ins 2-plfd
          Coil: left lock
          Flash: 4-big left mars
          Coil: knocker
          Flash: 2-ins 1-tar pit
          Flash: 2-insert 2-crane

          Any help or feedback would be greatly appreciated




          Sent from my iPhone using Aussie Arcade

          Comment


          • #6
            Originally posted by refisul View Post
            Hi,
            Your log was very helpful with many areas as I have the same one. But mine stopped working partially. I did a diagnostics test (coil/flash). 11 of 29 are not working. This causes no ball release. Everything else seems to work. But machine is now unplayable. Coils and Flash not working found...

            Coil: lockout
            Flash: 4-big rgt mars
            Coil: ball release
            Flash: 1-ins 3-plfd
            Coil: crane lock
            Flash: 2-ins 2-plfd
            Coil: left lock
            Flash: 4-big left mars
            Coil: knocker
            Flash: 2-ins 1-tar pit
            Flash: 2-insert 2-crane

            Any help or feedback would be greatly appreciated




            Sent from my iPhone using Aussie Arcade
            You do realise this thread is 5 years old?
            And welcome to AA.

            Comment


            • #7
              Yes I do sir, thanks for the reply, I had nowhere else to go, I didn't know what else to do for help. Any ideas or remedies for my issue? Thanks again


              Sent from my iPhone using Aussie Arcade

              Comment

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