Irem M72 multi kit installation & support

    This site uses cookies. By continuing to browse this site, you are agreeing to our Cookie Policy.

    • Hello,

      I’m having trouble getting my M72 multi working, I’m not sure what to try at this point, so I’m hoping somebody with more knowledge might have ideas.

      Symptom:
      I can't get a single game to boot. When the board is powered up, it hangs at the white garbage-sprite screen that all Irem boards start with. It never goes beyond the white garbage. This is true for every selected game (I’ve tried them all). Interestingly, the white garbage patterns differ depending on the game selected.

      The setup:
      Donor board is an Image Fight, confirmed working prior to conversion. Multi-board was purchased a week ago, it is a V2 multi-board.

      Things I've checked:
      • All jumpers on A board and C board are set per the specifications in install guide.
      • All dip-switches on A board are set to ‘off.’
      • Rom pack is Smokemonster pack, latest revision (V2), downloaded via link on this site.
      • I’m using 27C322 roms for all files except for rom 6, which uses a 27C160. All roms have been verified after writing.
      • Replacement GAL & MCU are installed, oriented correctly.
      • I’ve checked the pins on roms and pins on the multi-board to ensure nothing is bent or misaligned.
      • All boards are securely seated.
      • All cables are plugged in (including the one provided in the kit).
      • I only have one A & B board, but I have a pair of C boards; I’ve swapped out C boards just to be sure, I’m getting the same result with both C boards.
      • After running into this issue, I re-checked the donor with original roms, it functions as it should.
      Thank you in advance for any help or suggestions.
    • If no game boots at all I'd inclined to think that's a problem with the replacement GAL that goes next to the MCU.
      Maybe try to boot Image Fight on the multi with the OG GAL that came with your game.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • Apocalypse wrote:

      If no game boots at all I'd inclined to think that's a problem with the replacement GAL that goes next to the MCU.
      Maybe try to boot Image Fight on the multi with the OG GAL that came with your game.
      Thanks for the reply - I tried swapping the Multi GAL with my original GAL, it gives the same behavior (freezes at white garbage). Tried with my original GAL and original MCU, no change. Also tried with no GAL and no MCU, no change. In all three instances, the garbage on-screen is in the same pattern regardless of what GAL and MCU is in the sockets. If I change games via the dip-switch, the white garbage will be in a different pattern.

      What is the GAL-looking chip at socket 11 on the larger multi-board? Is that related to game selection? If I remove that GAL from the socket and turn the game on, the garbage is in a different shape.
    • @Luigi you mean if you select Image Fight on the multi and put back the OG PAL on the motherboard it doesn't boot?

      The GAL on the multi board is there for game selection right.
      What you could do is clearly identify both GALs that came with the multi (stickers?) and swap them.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • Mrhide wrote:

      Sometimes by donor dragon breed would freeze at /would not pass the garbled screen. a quick power off /power on would fix it.

      The same thing sometimes happen with the multi. Same fix works every time.

      You've probably tried this a few times right?
      I understand your board already had a problem before you installed the multi.
      That's expected for the issue to be still present after installation.
      In your case I'd say that's a reset issue, maybe a faulty capacitor in the circuit. Also please note reset is active high on V20/V30 CPUs.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • I appreciate all of the suggestions, thanks @Apocalypse, @Mrhide, @nem

      Tried a few things this morning:
      1) Tried swapping the two GALs provided in the kit.
      2) I tried putting factory-provided GAL in, selecting original game on multi.
      2) Checked voltage on the 27C322, it started at 4.86V, so I increased the voltage to a hair over 5V.
      3) Tried a quick on/off/on.

      Unfortunately still getting the same symptom in all cases.

      If it helps, here are MD5 checksums for my EPROMs and for the GALs.
      GAL (on C-Board) 8d834a74f36c140a2c6974cc8356af54
      GAL (on multi-board) 55429e23d2d2549ac87c78936e0db5e6
      01 - 15a5025f32eb59fca1f6f42a612562c5
      02 - 6a4174b96753a966a2149457a7a8ef64
      04 - 2525a5dc59664eba69540119f0334635
      05 - 45e21f985dfd448d0542f5f717d09e8b
      06 - af13e8b202370361d3007b97e3f41b91
      07 - d3ff0436e85a2da0352f42063be4d999
      08 - 9f6175907579b82e39b9ca2226441d5e
      09 - 7e5515d029ee5b08bffc933e2b2c2af8
      10 - 01e2c36ab792db72987ccb3f6eed4db9
    • I'm actually surprised you can read the content of the GALs. They should have been locked prior to shipping.

      I'm not even sure you can boot a game on the multi by installing its original PAL on the motherboard. Anyone else could try that, that's a 2 minute test?
      If it appears to work then maybe the GAL on the multi is bad. I had one guy having the GAL dying after only few hours of play. It happens. Once replaced he hadn't got any issue again.
      Looking for:
      - OutRun boardset even untested or not working
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), even with faulty PCM chip



      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • Apocalypse wrote:

      Mrhide wrote:

      Sometimes by donor dragon breed would freeze at /would not pass the garbled screen. a quick power off /power on would fix it.

      The same thing sometimes happen with the multi. Same fix works every time.

      You've probably tried this a few times right?
      I understand your board already had a problem before you installed the multi.That's expected for the issue to be still present after installation.
      In your case I'd say that's a reset issue, maybe a faulty capacitor in the circuit. Also please note reset is active high on V20/V30 CPUs.
      Yes that is correct : the multi has nothing to do with this freeze/reset problem: The donor board has the issue and I fully expected the issue to be present with the multi.
      Thanks for pointing a faulty cap and the reset. I can live with the issue now but will make a note for the future.
      +++
    • A long long time ago I fixed an intermittent sound problem on my Dragon Breed.

      Solved intermittent problem with sound on Dragon Breed.
      No music would start upon first power up but after a reset
      we had sound.

      YM2151 did not have enough time to reset itself.
      Actually pin3 of the chip is not connected at all.
      By soldering a 220uF capacitor across pin3 (Initial Clear)
      and ground we keep the YM2151 in reset long enough.

      Maybe something similar is happening ?
      The future of ST-V rests upon our work and your work