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Taito Captain Zodiac Repair Log


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

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  • Taito Captain Zodiac Repair Log

    I've been working on this board for yonks and finally made some progress tonight.

    Overview of the board:
    Early 90's era Taito punching game which runs a dot matrix display. Some similar hardware to Taito System B. Full overview of the ICs, including board pictures and manuals etc below.

    As this game was undumped, I contributed the dump to the MAME team for preservation.

    Repair Log - In Chronological order from top to bottom.

    Original state of the machine...
    • Machine had DC power supply removed and the buttons on the top control panel unplugged.
    • Looks like the machine may have been exposed ot the elements at some time due to lack of back panel.
    • Some of the EPROM stickers were gone - concern that UV damage may have led to bit-rot."

    First set of repairs...
    • Installed new DC power supply, step down transformer and AC line filter. Re-connected the buttons.
    • Machine powered on, with garbled video output and some lights flashing and motor movement. No sound. Machine then went dead. Symptoms would not repeat if the machine was re-started. I had to wait 24hours between re-starts to repeat the same garbled start-up.

    Decided to try the MAME dump
    • Someone had beaten me to the punch in dumping and contributing to MAME, however I had a sneaking suspision that I had a different set.
    • Dumped ROMs to compare to MAME.
    • MAME Roms different by a small amount.
    • Burnt MAME roms and replaced factory set.
    • No joy - exact same issue as above.

    Found some corrosion in the resistor packs...
    • RRCD1 and RRCD2 (chips labelled CDR-1E2B 2L) had corroded legs.
    • RRCD2 had to have legs resoldered on from another chip.
    • RRCD2 had corrosion repair via fiberglass pen.
    • No change in behaviour after repairs

    Logic Probing and CPU replacement #1
    • Logic probe testing found no output on many of the legs of the TMPZ84C00AP-6 at IC22 location.
    • Removed chip, added socket and replaced with a new TMPZ84C00AP-6.
    • Machine boots to nothing on the screen, no motor movement or lights - i.e. no sign of activity in the outputs. However, the TMPZ84C00AP-6 at IC22 now has some sort of logic output on all legs.

    Replaced all of the SRAM
    • Removed all lh5168d-10l (SRAM) chips in all three locations on the PCB. (IC19, 20 & 28)
    • Accidently lifted pin 24 on the lh5168d-10l at IC19 location.
    • Tracked the damaged trace to the EPROM 27C512 at IC14 location. Believe to be also be connected to 24 on the 27C512 also so made a patch repair on the underside of the PCB.
    • Replaced all lh5168d-10l SRAM chips into the sockets.
    • No action at all

    Replaced anopther CPU
    • Removed the existing tmpz84c30ap-6, socketed and replaced with a new chip. Lifted a trace on pin 12 so had to run a repair.
    • Game now boots and appears to run as per normal except for lines in the display. Suspect that this may be related to a bad connection elsewhere.

    Next I need to track down the bad graphics issue. I have a suspicion that the lifted track between pin 24 of the 27C512 and pin 24 of the SRAM (lh5168d-10l) may be related. I took a punt in repairing this trace. Does it seem odd that the pin 24 of the EPROM and pin 24 on the SRAM are address lines tied together?

  • #2
    Spent a bit of time on this tonight. As per another thread, I was trying to figure out if I had a bad connection between the address lines of one of the Z80 derivative chips (IC22) to the SRAM (IC20). I thought that this may have been the cause of the line through the display that I had in the last video. After making the repair as per the terrible diagram below, I found it made no difference, at least not initially. After about 20 seconds the lines disappeared and the display was all good. I even went so far as to remove the repair to see if the lines returned but they did not. Here is the repair I made...

    Click image for larger version

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    I suspect the Z80 derivative CPU at IC22 (TMPZ84C00AP-6) may be more related to the sound generation than to the graphics. I did toggle the attract sound on but got no output. This could be because I don't have the full wiring harness in place, and I think that there is volume attenuation in the test panel which is still in the cabinet.

    Here is a video of where I got to tonight.

    Here are some other observations.
    -I mixed and matched the ROMS between the original data ROMs and the MAME ROMs. I noticed zero difference in the attract mode between the two.
    -If the game detects a motor error/sensor error in the skull, it will reboot the machine before the cinematic where Captain Zodiac crashes into the planet. Below is a video that shows the resets caused by the error. (error occurs at 22 seconds)

    I also started working on the lamp board. These use a set of six JC202PC2 solid-state relays to control a set of 6 pairs of incandescent bulbs. Somehow, one of my sold state relays went missing from the lamp board so I had to replace it with an AliExpress one. Turns out it is shit. It just stays turned on. If anyone can help me locate a proper one of these that would be super.

    On a related note - does anyone know how Xenon flashers work? I am getting 100V to the flasher assembly, just no flashing.
    Last edited by Berty; 30 August 2019, 08:03 PM.


    • #3
      Progress has been made on the Taito Lamp Board Controller repair.

      The Lamp Controller Board uses ground and 5V DC to trigger a 100V AC feed through a set of solid-state relays. These relays are labeled as JC202PC2. For whatever reason, my board was missing one of these. I sourced one from Aliexpress and it didn't work. It just stayed on constantly as you can see in the video below where I have started re-assembling the machine...

      The video also shows the full Captain Zodiac Attract Mode too which is kind of cool for its use of DMD animation.

      Instead of rolling the dice and buying another from Aliexpress, I went to RS to find a suitable replacement which matched as close as possible what was on the spec sheets of the JC202PC2. This ended up being an "Omron 2 A SPST Solid State Relay, Zero Crossing, PCB Mount, Phototriac, 264 V ac Maximum Load".

      Click image for larger version

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      In the picture above you can see the Omron relay versus the JC202PC2. Although the DC input legs line up to the Taito PCB mounts, the AC legs did not.

      Click image for larger version

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      In true backyarder form, I modified the original PCB with a power drill and a fiberglass pen to accommodate the new relay.

      Here is the result!

      Click image for larger version

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      The good news is that the surgery went according to plan and now the lamps are working

      Another thing that I did while the machine was pulled apart was to replace the incandescent bulbs (E17) with some LED ones.
      Last edited by Berty; 31 August 2019, 07:21 AM.


      • #4
        Nice work mate, good to see you making progress on it.
        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


        • #5
          Two steps forward, one step back.

          I managed to get the game all assembled and working...

          ...however it now resets whenever I coin it up, or use the service switch. I have reseated the connectors as well as ensuring that it has correct voltage but no joy yet.

          Any ideas on where to look for this fault? I am wondering if I need to double check the program roms against the original dump.

          One other interesting thing is that the Test mode button doesn't trigger the test mode. The button is fine, but wondering if it is related to an issue with the resistor packs.


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