Announcement

Collapse
No announcement yet.

Taito L-Shaped PCB Repair Log - GG#1

Collapse

Share any logs or helpful information you may have to repairs of arcade PCBs, Monitors etc

X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Taito L-Shaped PCB Repair Log - GG#1

    When I first plugged the board in, it was totally dead, after replacing the crystal it came to life and was booting to garbage.



    The CPU and 74154 were removed and socketed and confirmed working on another PCB.
    All ROM sockets were replaced and a test ROM was fitted.
    Still not much change, after a bit of probing around I found one of the 75157s was faulty, replacing it brought the board back to life and the Test ROM showed two faulty RAM which were socketed and replaced.

    A set of Lunar Rescue ROMs were fitted and the game booted up but had a slight glitch, as the ship descended there were lines above and below it. If either of these lines touched one of the enemy ships it would explode as seen in the video below.



    I spent a lot of time scratching my head over this one and took a fresh look at it today.

    I could see MX4, 5 & 6 active when the ship was dropping so I started to look around that area. The pull-up resistor block checked okay so I started to check continuity from the interconnect edge connector pins back along the MX lines to the 74153s.



    Pin 36 tested open circuit so I reflowed the connector with no improvement.

    I ran a trace wire from the via directly to the pin on the interconnect and that fixed the problem.



    The board is now fully working.

    [MENTION=6328]lentildude[/MENTION]
    Namco Starblade - Taito Cocktail 14" x 3, 20" x 2 - NZ SI PtII Upright - Chase HQ DX, Taito Top Speed - Taito Grand Champion - Taito Safari - LAI SI Head to Head Cocktail - SI Cocktail Clone x 2, Pong Clone x 3

  • #2
    Hey [MENTION=2995]Kaizen[/MENTION]

    Would you be interested in reviewing a Midway 8080 doc I'm putting together?

    Comment


    • #3
      Originally posted by channelmaniac View Post
      Hey [MENTION=2995]Kaizen[/MENTION]

      Would you be interested in reviewing a Midway 8080 doc I'm putting together?
      Yeah sure, shoot me a PM if it's easier.
      Namco Starblade - Taito Cocktail 14" x 3, 20" x 2 - NZ SI PtII Upright - Chase HQ DX, Taito Top Speed - Taito Grand Champion - Taito Safari - LAI SI Head to Head Cocktail - SI Cocktail Clone x 2, Pong Clone x 3

      Comment


      • #4
        Thanks,

        I should have a first draft ready over the weekend. I'll just need an email address.

        Comment


        • #5
          Nice one Kaizen.

          I find these boards fun to fix. .. but sometimes a little bit on the infuriating side. Good to see a fellow spacey repairer smashing it!

          Comment


          • #6
            Necro bump... I finally got the doc to where I wanted it after a bit more work. It's 40 pages long and on the way to you.

            Edit: Thanks to another reviewer, it has more pictures, a minor tweak to the note about the DIPs and is up to 44 pages.
            Last edited by channelmaniac; 12 April 2020, 09:39 AM.

            Comment


            • #7
              Cheers mate, looking forward to checking it out.
              Namco Starblade - Taito Cocktail 14" x 3, 20" x 2 - NZ SI PtII Upright - Chase HQ DX, Taito Top Speed - Taito Grand Champion - Taito Safari - LAI SI Head to Head Cocktail - SI Cocktail Clone x 2, Pong Clone x 3

              Comment

              Users Viewing Topic: 0 members and 1 (guests)
              Working...
              X