No announcement yet.

Konami Justifier replacement light sensor? (phototransistor)


Any brand of Game Consoles, hacks , mods, tips , or anything ya like...

  • Filter
  • Time
  • Show
Clear All
new posts

    Konami Justifier replacement light sensor? (phototransistor)

    Hello All,

    I've been searching and trying to find a working replacement for the Konami Justifier gun's light sensor for months now. I've checked everywhere I could on the internet and it all comes up with dead ends and others trying things that didn't work. I've been told that the sensor could quite possibly be a custom part that is actually a phototransistor with a built in op amp? The part itself is unmarked aside from the die number on the back of it. There is no part number at all. I even took a shot in the dark and put in a service ticket with Konami and when they got back to me it was to sadly say their parts division is closed and they just recomended a 3rd party vendor they are sending people too now. That was only for Arcade parts as well, not specifically for 30 year old console hardware. I've tried many different phototransistors and I even tried building an amp with a LM741 but it must be too slow as it's only 1mhz and it needs something faster? I was told if it is a custom phototransistor with built in amp, it might need something as high as 10Mhz but I personally don't know how to make that circuit or if it would even work.

    I was also told that the amp could be inside the custom chip Konami had controlling the gun which is in the handle. The sensor board itself it pretty simplistic with only the sensor, a 1k resistor and a .1uf smoothing cap. I took a shot at contacting the guy who posted the player 1 blue gun to player 2 pink gun mod thinking he might know the solution but was unable to find a proper contact for him from his blog posting. I got a little discourage when his name brought up a more recent google search which it saoid someone with his name and similar credentials in the same area had passed this year. Here is a link to his mod he posted back in 2015:

    Mark Wylie's Blog: Sega Konami Justifier Hack: Convert Player 1 (Blue) Gun to Player 2 (Pink) Gun

    Here is a pic of the sensor and board from inside the justifier gun:

    I have tried many different phototransitors so I can list what DOES NOT work from my experience so far:

    LM741 op amp ciruit with a tept5600 series sensor, 1meg resistor in parallel with a 22pf cap & 2k variable resistor does not work

    L14G1 (I think I tried this one without success but I've tried so much now I forget if this failed too)

    TSL252R do not work

    TSL235R do not work

    OPL550 do not work

    My ultimate goal was not just to find a replacement for the sensor for broken guns but also to be able to post a DIY method for anyone to build
    there own player 2 gun out of something super cheap like a $5 NES Zapper clone as the shell base cause the pink gun is really nothing more
    than the sensor and a 6p6c cord attaching to the player 1 gun. I think there is a lot of people who would love to not only be able to fix dead Justifier
    guns but also be able to build there own 2nd player guns for $10 instead of paying upwards of $100 for an original pink player 2 gun that the market
    is now commanding for them.

    control board inside player 1:

    player 2 schematic:

    op amp I built that DIDN'T work with this gun:

    Click image for larger version  Name:	sensor & amp.png Views:	0 Size:	17.1 KB ID:	2144665

    After so many years I would have thought the solution to this problem would have been long ago posted to the internet
    as common know how but alas it's not. I really hope this can be finally put to bed and a working solution can be plastered on the web to overtake all
    the old dead ends from others not being able to find a way to make this work.

    How is this for a wall of text for a first­čść

    TL;DR: Know a good replacement for the light sensor in the Justifier gun?


    I have been curious to find out if the namco light sensor out of a time crisis gun would work but I'm not paying $45 for one to find out. I tried asking an arcade part seller what the part number is on that sensor but he told me the distributor doesn't share that information (because of course they won't, that would help make life a hell of a lot easier in this )

    Click image for larger version

Name:	namco sensor pcb.jpg
Views:	31
Size:	196.8 KB
ID:	2144689


    Users Viewing Topic: 0 members and 1 (guests)