It's too low. You have something wrong either at the power board or with anything else that might use the 12V system. It should likely be somewhere around 15V as it's unregulated).

The power boards for Capcom have the same issue that WMS driver boards do, the solder joints can fail and need to have trace mods done to eliminate the problems. I have had issues with the lamp matrix since one side draws far more current than the other.

Unplug J15 from the power board (this powers the playfield) and see if the game boots. If it does, measure the voltage at pin 11 on J15 and see what the voltage is. If it still reads 10V, then the problem isn't on the playfield.

Unplug J18 from the power board (this powers the cabinet). Test voltage at pin 7 on J18 for 12V as above.

Finally unplug J16 from the power board (this powers the backbox). Test voltage at pin 11 on J16 for 12V as above.

If you still don't see an increase in the 12V when unplugging any one of the three, unplug ALL three and test for 12V at any one of the pins above. If you finally get a proper voltage, it may be that you have to replace C11. If the trace is bad to C11, the 12V line may not be a true flat DC, but may be full-wave rectified, which means most DMMs will not read it accurately (it will read lower than expected).

Hope some of that helps!

Tony

This is why I believe it's an issue with the power supply board, particularly C11.

Let us know what you discover!

Tony

I still wouldn't necessarily point fingers at the opto system just because the game won't boot with J15 plugged in.

Not sure if it was clear in your post, but with J15, J16, AND J18 (all three) unplugged, you still only have 10V? If so, you most definitely have a power board issue. It's either the C11 cap, the bridge rectifier BR5, the traces that connect them, or the wiring harness attached to J19.

I'll see if I can take some pics of one of my power boards for you to identify some key points.

Tony

topside of power board Here's a labeled picture of the topside of the power board so you can know which parts we're talking about.

First set of points The circled areas are grounds and should be jumpered together. As you can see from this example, a couple are already jumpered. The key one you need to be worried about is the ones I have labeled "connect" which is the ground that goes between C11 and BR5. You might check for continuity between those two points, but I'd just go ahead and add the jumper anyway.

Second set of pointsNot sure if your game uses J19 or J20, they all tie together anyway, so this would be the 12VAC coming in that goes to bridge rectifier BR5. Check this line for continuity first, but it wouldn't hurt to add a jumper anyway.

Third set of pointsThis is the other 12VAC line that you may want to consider adding a jumper to after you have checked for continuity.

Hope that helps some.

Tony

I'm not convinced that you'll need to replace C11, but I also wouldn't be surprised either. The caps are nearly 20 years old after all!

I would try adding the jumpers in first, if you still don't get anything more than 10V, then you'll want to start replacing parts.

Of course I'd also be looking at the 12V line under an oscilloscope as that would definitely tell me what's really happening. Without that kind of knowledge, I would probably replace both BR5 and C11 if you don't see any improvement in adding the jumpers.

And as for the jumpers, use the heaviest gauge wire you can reasonably solder to those small pads. 18 AWG would be the minimum I'd suggest. 16 AWG if you have it.

Cheers,

Tony

Glad you got it working!

Cheers,

Tony