CPS2 system multi cart not working

[antonioad14(TWON)]

Bought this CPS2 off of some guy who showed it to me working, upon testing it myself on my supergun I can't seem to get it to boot a game at all. On 1944 I just get this yellowish green screen and when testing Giga wing I get a screen with some glitchy graphics followed by a white screen. Did I set it up wrong? I feel it should be good. I already tried reseating it multiple times with no success.

 

[ekorz]

I don’t want you to take this the wrong way but that is the most frightening looking supergun I’ve ever seen. Is the jamma harness keyed? Is the supergun keyed?

Is the psu adequate for a large pcb? What model is it?

A key ensures the alignment for the power from the supergun to the pcb, and my guess is either the harness is not aligned somewhere or the psu is not sufficient.

This is a key

 

[antonioad14(TWON)]

I don’t want you to take this the wrong way but that is the most frightening looking supergun I’ve ever seen. Is the jamma harness keyed? Is the supergun keyed?

Is the psu adequate for a large pcb? What model is it?

A key ensures the alignment for the power from the supergun to the pcb, and my guess is either the harness is not aligned somewhere or the psu is not sufficient.

This is a key

I believe the PSU is 12 volts, but the supergun is set to 5V so I thought it should be good. Also this is how my jamma is connected, I believe it should be fine

 

[ekorz]

I believe the PSU is 12 volts, but the supergun is set to 5V so I thought it should be good. Also this is how my jamma is connected, I believe it should be fine

that is probably not fine, do you have another supergun you can test with? Ideally with no harness at all, or a different one?

Your PSU is probably not powerful enough of a 12v supply to be split into +5 and +12 v, and then sent down that harness. The CPS2 is a large board that needs a lot of current. Similarly your harness looks pretty long, and is only connecting one of the 5v lines and grounds. A typical JAMMA setup uses 2 wires for 5v, and 2 wires for ground. (that's the red and the black). Honestly the black barely looks like its connected too.

Red box is 5v, see the pad that's not connected? Black box is the ground, also missing a pad.

At the other end, both of the GND and 5v pins are connected, but it's not actually running through two wires...

Anyway if you get a multimeter and probe the 5v and GND lines at the PCB, while it's powered, you probably will not see 5.00v even though that supergun is reading 5.14v.

 

[antonioad14(TWON)]

Thanks for the info, I would like to directly connect it to the super gun but the plastic casing around it makes it impossible. Would like to get something like a HAS supergun but simply can't get my hands on it. Unfortunately this is the only one I currently have. But I've seen other people online power up the CPS2 just fine with this supergun. Although maybe the harness might be the problem.

 

[ekorz]

Thanks for the info, I would like to directly connect it to the super gun but the plastic casing around it makes it impossible. Would like to get something like a HAS supergun but simply can't get my hands on it. Unfortunately this is the only one I currently have. But I've seen other people online power up the CPS2 just fine with this supergun. Although maybe the harness might be the problem.

You could try removing the shell on the A board but then you’d have to reseat it all together.

The HAS or minigun would of course be the sure fire way to get it working, but you’d also need a new psu.

Maybe you can find someone locally who has an arcade setup where you can test, but I’d imagine the cps2 is fine.

 

[antonioad14(TWON)]

You could try removing the shell on the A board but then you’d have to reseat it all together.

The HAS or minigun would of course be the sure fire way to get it working, but you’d also need a new psu.

Maybe you can find someone locally who has an arcade setup where you can test, but I’d imagine the cps2 is fine.

Thanks for your input, got a minigun on the way so I'll see if that does the trick.

 

[ekorz]

Thanks for your input, got a minigun on the way so I'll see if that does the trick.

cool, make sure you buy a compatible power supply too. even the cheap arcade power supplies will have +5v,+12v,-5v dedicated outputs (though the cps2 doesn't need the -5v line you might as well wire it to the minigun anyway)

 

[kazuo]

Out of curiosity, what power supply are you using?

If you want to rule out the harness (which admittedly appears to be not the best), you could de-case the CPS2 as ekorz suggested and then try it. Since you saw it working before you got it and trying to reseat the boards didn't seem to help, it is either the harness and/or the power supply.

5.14V at the SuperGun seems high to me. Do you have a meter to verify what the board is getting at the JAMMA edge? If not, you should get one, it's pretty much a requirement in this hobby.

 

[antonioad14(TWON)]

So I got everything, minigun arcade power supply dialed in 5V and everything and I'm pretty much getting the exact same issue I was before, no audio either. Tried cleaning the a and b board but there's only so many times I can reseat this thing.

 

[antonioad14(TWON)]

I also noticed that if I apply pressure to the B board upon boot it'll sometimes stay at a black screen, but if I boot it up without applying any pressure it usually stays at a solid color screen.

 

[antonioad14(TWON)]

Okay so I switch over to Megaman power battle 2 and got a "ram error" screen.

 

[antonioad14(TWON)]

I opened the shell and noticed some of the dark soft chips inside were loose so I brought those all back together and connected it to the A board without its shell and eventually got the graphics to work. All that's left is to figure out the audio.

 

[antonioad14(TWON)]

Okay so small update, I got the audio working by holding down the volume button in the system for 5 seconds from boot. And now everything works as it should. Only problem is now once I put the shell back on it's harder to make a proper connection to the A board, everything works fine but I get these white lines across the screen.

 

[antonioad14(TWON)]

But if I try to seat it with the B board exposed it much easier to find that "sweet spot" where those lines go away.

 

[antonioad14(TWON)]

Ended up opening it up again and realized the cable that the LCD connected to was putting alot of pressure on the board so I gave that some more room and upon reassembling it, and giving it some good reseats it's now fully working with the shell on! Finally can lay this project to rest, just gonna enjoy it now

 

[kowal]

It’s good that it works, but going back to the wiring - I know these harnesses, they’re the cheapest extension cables you can get. The quality of the power lines is terrible, and I’d recommend replacing the wires. Either use a full pinout with AWG 22 (x4), or replace the GND and 5V lines with AWG 16.

The cables in these cheap harnesses have more insulation than actual conductor inside. In reality, this is more like AWG 25. AWG 24 can reliably handle about 0.5A, and with a very short harness maybe around 1.5A, but I would always stick to the proper rated values.

The CPS should have a constant 2-3A supply, so you’d normally need around four of those wires for that current, yet here everything is running through a single one.