Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Discussion of development of software for any "obsolete" computer or video game system.
lidnariq
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Wed Mar 18, 2020 1:03 pm

I mean, there's so little silicon there's not much that can go wrong. It's basically:
1- The phototransistor, which tentatively seems to be working
2- The next transistor, the small SOT23 near the inductor(?)
3- The LM311

Unfortunately, I'm not really certain how to go about testing these things without at least a schematic first, and I'm uncomfortable with trying to reverse-engineer one from your pictures.

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Wed Mar 18, 2020 1:30 pm

lidnariq wrote:
Wed Mar 18, 2020 1:03 pm
I mean, there's so little silicon there's not much that can go wrong. It's basically:
1- The phototransistor, which tentatively seems to be working
2- The next transistor, the small SOT23 near the inductor(?)
3- The LM311

Unfortunately, I'm not really certain how to go about testing these things without at least a schematic first, and I'm uncomfortable with trying to reverse-engineer one from your pictures.
I understand. Your input is very valuable to me so please do continue as you see fit. The first thing I considered when opening the gun was replacing the LM311. That SMD transistor next to the inductor(?? from me too, I'm still not 100 percent sure what it is) would make sense to test as well. There is very little logic on the board correct, mostly smd caps and I'll have to have a closer look, but some smd resistors as well.

Only issue with replacing the transistor right now is all I have on had is 3904's as that is what I use for simple transistor video amps.

I was able to find a simple lightgun test routine program that I'm gonna burn a copy of and try out this afternoon to see if that will give any further information on diagnosing this problematic gun. Heck by the end of this I might be able to make these damn things from scratch :P

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Wed Mar 18, 2020 4:47 pm

After running the test program I can report back that it doesn't detect the gun at all. After manually entering it as a justifier, menacer or gamegun it still registers nothing. I have my work cut out for me here it seems :(

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Wed Mar 18, 2020 4:50 pm

At the very least, the trigger should show up on a generic pad tester...

Do you know that your GAMEGUN is specifically compatible with the Sega CD and not the 3DO?

Since you disassembled yours, you could see what pin on the wires to the board connect to what pins on the DE9 connector on the other end.

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Wed Mar 18, 2020 8:11 pm

lidnariq wrote:
Wed Mar 18, 2020 4:50 pm
At the very least, the trigger should show up on a generic pad tester...

Do you know that your GAMEGUN is specifically compatible with the Sega CD and not the 3DO?

Since you disassembled yours, you could see what pin on the wires to the board connect to what pins on the DE9 connector on the other end.
Ya the trigger does respond. In Lethal Enforcers it is able to move from one choice to the next in the menu. It is the sega CD version not the 3do version. The 5 wires that are coming from the female DB9 are as follows: pin 1 is there as a white wire (attached to the trigger), pin 4 is present as a brown wire that is attached o the bottom of an SMD 4751 that then branches to 2 more of those same 4751's that attach to both sides of the trigger wires on the other sides of them, pin 5 is there as an orange wire which goes to pin 8 (VCC) of the LM311 , pin 7 is grey wire attached to VEE pin 4 of the LM311, and of course pin 8 is black (gnd).

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Wed Mar 18, 2020 10:27 pm

That is 100 percent an inductor I've finally figured out.

It's a 5.6 mH, ±10% inductor. Cool thing is you can add and divide inductors the same way you can with resistors. I mention that as it seems 5.6mh isn't a common unit from what I've gathered so far.

That little transistor below it is actually a 3904 equal. The SMD stamp is 1MD which translates to being an smd package of the 3904 full sized one.
I've read out the rest of the caps and resistors as well. You pretty much have to buy in bulk with these things so I might just end up drawing the pcb afterward for all the extra parts I'm gonna end up with. Maybe make a board to stick inside the common blue justifier so it can have added menacer support as well. Who knows. This lightgun is now a mission. I got taken for a ride on this one as I bought it from a seller who claimed it was in full working order. I knew $55 was too cheap for one of these but I thought I might have scored a good deal. I scored a good deal alright, a good deal of work to get it working again..lol...

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Wed Mar 18, 2020 11:10 pm

If you get me better pictures of the PCB - both sides, full PCB in view, no glare, as many traces visible as possible - I can probably draw a schematic for you.

Some things I'm really not clear on. DE9 pin 7 should be TH, the photosensor output, but LM311 pin 4 is the negative voltage supply rail, and that doesn't make sense to have those connected.

Both the Menacer and the Justifier have at least one extra button beyond the trigger - does yours have one?

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Thu Mar 19, 2020 12:46 pm

lidnariq wrote:
Wed Mar 18, 2020 11:10 pm
If you get me better pictures of the PCB - both sides, full PCB in view, no glare, as many traces visible as possible - I can probably draw a schematic for you.

Some things I'm really not clear on. DE9 pin 7 should be TH, the photosensor output, but LM311 pin 4 is the negative voltage supply rail, and that doesn't make sense to have those connected.

Both the Menacer and the Justifier have at least one extra button beyond the trigger - does yours have one?
Yep it has another button. It's the back button shown on the back side of the pcb in the photos. Maybe I didn't upload that one. I'll get the best pcb pics I can. I was thinking of that already as well. I'll lift up the 2 diodes and the inductor so you can see under them as they do bridge across other population on the pcb.

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Thu Mar 19, 2020 6:51 pm

lidnariq wrote:
Wed Mar 18, 2020 11:10 pm
If you get me better pictures of the PCB - both sides, full PCB in view, no glare, as many traces visible as possible - I can probably draw a schematic for you.

Some things I'm really not clear on. DE9 pin 7 should be TH, the photosensor output, but LM311 pin 4 is the negative voltage supply rail, and that doesn't make sense to have those connected.
I had the black and grey mixed up. Black is going to pin 7 not pin 8. It really throws me off when color coded wires have black as anything else but ground. Grey is pin 8 on this cable for some messed up reason. There is 1 cap and 1 resistor(??) that I don't know the values of as the are not marked. I assume the cap is just another .1uf to smooth voltage but I could be wrong. Solider side of the pcb is obviously flipped when considering matching it up with the top side. That single diode I assume is a common switching diode but I'll take it off and read it soon here. I'm just burning out right now.
DSCF0325.jpg
DSCF0327.jpg
EDIT: I also don't know the values or how to read those 2 tantalum capacitors(??) marked "10-16 E3". Do you?

I can overlay them if that helps, sounds like you know whats going on here and that won' t be needed though.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by TmEE » Thu Mar 19, 2020 8:13 pm

Image
This should be accurate

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Thu Mar 19, 2020 8:27 pm

TmEE wrote:
Thu Mar 19, 2020 8:13 pm
Image
This should be accurate
So what are you decerning the values of the 3 caps are that I didn't label? Your paint writing is kinda hard for me to read and I don't want to make assumptions. It looks like 10nf or is that 10uf on the 2 polarized ones? The little grey one I left unmarked I don't even know for sure what that is. The one below the positive side of the zenner diode.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by lidnariq » Thu Mar 19, 2020 8:38 pm

You should be able to solder a TO-92 BJT onto the SMT pads if you want to try replacing it without buying a new SMT one.

You should be able to measure voltages on the device while powered to figure out what's gone wrong. You should see:

Pin marked "E" on phototransistor go from ≈0V when dark to something higher when light is shining

Inductor at contact next to 2N3904 should go from ≈5V under constant illumination to something lower as light gets brighter.

One thing I really don't understand: LM311 pin 1 is both connected to ground via 4.75kΩ resistor on component side, and directly connected to ground via traces on solder side??

Voltages on inputs to LM311 should be:
* 3V on pin 2 under constant illumination (getting lower when light gets brighter)
* 2.5V on pin 3 always
* 5V on pin 7 during constant illumination, becoming 0 while light gets bright enough fast enough
nintendo2600 wrote:
Thu Mar 19, 2020 8:27 pm
So what are you discerning the values of the 3 caps are that I didn't label?
I agree with TµEE that they're probably 10µF. (My best guess is 10-16 means 10µF, 16V)

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nintendo2600
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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Thu Mar 19, 2020 9:06 pm

lidnariq wrote:
Thu Mar 19, 2020 8:38 pm
You should be able to solder a TO-92 BJT onto the SMT pads if you want to try replacing it without buying a new SMT one.

You should be able to measure voltages on the device while powered to figure out what's gone wrong. You should see:

Pin marked "E" on phototransistor go from ≈0V when dark to something higher when light is shining

Inductor at contact next to 2N3904 should go from ≈5V under constant illumination to something lower as light gets brighter.

One thing I really don't understand: LM311 pin 1 is both connected to ground via 4.75kΩ resistor on component side, and directly connected to ground via traces on solder side??

Voltages on inputs to LM311 should be:
* 3V on pin 2 under constant illumination (getting lower when light gets brighter)
* 2.5V on pin 3 always
* 5V on pin 7 during constant illumination, becoming 0 while light gets bright enough fast enough
nintendo2600 wrote:
Thu Mar 19, 2020 8:27 pm
So what are you discerning the values of the 3 caps are that I didn't label?
I agree with TµEE that they're probably 10µF. (My best guess is 10-16 means 10µF, 16V)
OK, I'll test those conditions you mentioned and report them back after I have done so.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by TmEE » Fri Mar 20, 2020 4:39 am

nintendo2600 wrote:
Thu Mar 19, 2020 8:27 pm
So what are you decerning the values of the 3 caps are that I didn't label? Your paint writing is kinda hard for me to read and I don't want to make assumptions. It looks like 10nf or is that 10uf on the 2 polarized ones?
The polarized ones are 10µF 16V tantalums.
The little grey one I left unmarked I don't even know for sure what that is. The one below the positive side of the zenner diode.
This one I seem to have missed but since it is a ceramic between power rails it most probably is a 0.1µF part.

The light colored one near the transistor is some low value capacitor, probably 100...1000pF. It will control high freq response of the amp circuit in there. There is some sort of bandpass filtering (all the series caps and that inductor) going on so constant light tests will probably not get you far. Something like a CRT screen or a CFL bulb should show some results measurable with a multimeter.

If there is a problem anywhere it is the diode, transistor or the comparator. You can safely force the comparator input (short the 100 or 150k resistor after one 0.1µF cap) and see what the output does, if it doesn't respond you know the comparator is faulty.

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Re: Hardware test program for Genesis Justifier, Menacer and\or ALG GAMEGUN?

Post by nintendo2600 » Fri Mar 20, 2020 5:11 pm

TmEE wrote:
Fri Mar 20, 2020 4:39 am

This one I seem to have missed but since it is a ceramic between power rails it most probably is a 0.1µF part.
The diode that is marked 1nXXXX has lost it's markings on the rest of it aside from 1n4 and possibly another 4 under it. It might have already been broken cause when I removed it with my hakko 808 it poped right in my face. Never had that happen before. another inch up and the little fleck of glass would have gone in my eye...lol.. Anyhow, so that is most likely an 1n4148 correct? or would it be something else? I'm ordering a whole new set of guts for this thing from Digikey tonight.

Also, how does this phototransistor look to you guys? wavelength is 830 not 800. It even has a metal can :)


https://www.digikey.ca/product-detail/e ... =321383067
Last edited by nintendo2600 on Fri Mar 20, 2020 5:23 pm, edited 1 time in total.

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