Recent content by ic3b4ll

  1. ic3b4ll

    How to dump 1mbit mask roms from a konami 80's pcb

    There are two types of 1 megabit ROMs with slightly different pinouts. Those are mask ROMs so I'd expect them to use... Mask ROM pinout. Search for 27c301 pinout, it's the same as the one used on mask ROMs. If your programmer doesn't support this type you can make a simple adapter to the more...
  2. ic3b4ll

    Hello from Germany!

    Hello!
  3. ic3b4ll

    Weird Raiden Fighters issue

    Bad checksum may mean that the flash chip on the motherboard is bad. You could try to replace it.
  4. ic3b4ll

    MV4 top board issues, only slot 1 works

    What @ack said :)
  5. ic3b4ll

    MV4 top board issues, only slot 1 works

    What version of the MV4 is it? The big one with loads of ICs or the newer with SMD customs?
  6. ic3b4ll

    MV1FZNB2 Garbage Screen/Green Screen Loop

    I don't think you've created a mess for yourself, just changing the volume wouldn't have caused the board to stop booting. With that said, it's a rather strange situation. Start by checking the voltages at the board edge and, if your board's BIOS is socketed remove it and insert it again. If...
  7. ic3b4ll

    Mystic warriors pcb arent showing sprites.

    It's not bad if the sprites came back. There's probably a bad via or pad connection underneath the chip itself. Proceed as @stj described and check if the vias connected to the pads have continuity before resoldering the chip.
  8. ic3b4ll

    Mystic warriors pcb arent showing sprites.

    Maybe my wording wasn't the clearest. I was suggesting getting the normal running temperature range of good ones to compare with suspected bad ones. It would help with basic troubleshooting I think.
  9. ic3b4ll

    Mystic warriors pcb arent showing sprites.

    Oh, another thing. If either chip is *hot* it's shorted and therefore dead. Maybe we should start taking temperature measurements of normal functioning chips for reference. What do you think @Hammy ?
  10. ic3b4ll

    Mystic warriors pcb arent showing sprites.

    Very bad solder joints on these things... Place the board on a flat non-conductive surface. Turn it on. Apply pressure to the 55555 and the other chip like it and see if glitches appear. Alternatively, gently (gently!) touch the pins of the chips. With dry hands of course. If glitches appear...
  11. ic3b4ll

    Raiden Fighters Jet no power.

    The Z80 you used is fine. My RFJ is stored away otherwise I'd check it for you. The fact it always hangs in the exact same spot suggests that whatever is causing the freeze is probably related to a memory access. If you have the means to dump the program ROMs (main and audio CPU) I'd try that...
  12. ic3b4ll

    Raiden Fighters Jet no power.

    Make sure the Z80 is fast enough. I think it's a 6 or 8 MHz part. The reset button should (gasp!) reset the board. Now that I think of it, I had to resolder it too, it had the same behaviour as yours. Start with the oscillator and reset switch and see if the problem goes away. Grab a logic...
  13. ic3b4ll

    Raiden Fighters Jet no power.

    Yes, just the 4 pins underneath. My board had very little solder on those pins. Try applying pressure or slightly flexing the board to see if it behaves differently -- freezing sooner or later, glitching, etc. This would indicate cold solder joints on one or more SMD chips -- usually this...
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