Capcom IO Naomi to Jamma PCB, schematic, pics or info please

[Madbury]

Hi,

I'm a cheapskate so I picked up a broken Capcom Jamma to JVS IO adapter from ebay and I'd like to try and fix it. After a quick physical inspection I can see that it is missing a few components. For starters it is missing 3 NEC PS2801-4 ICs, which look as though they are to isolate the Jamma connector from the rest of the board to prevent interference. I'm not especially concerned about these parts, it will be a tricky surface mount solder, but they look to be replaceable and I suspect the board will still function (partially) without them.

The bit that has got me stumped are the spare pads for a large component which mounts alongside the Hitachi CPU. This is marked as 'X1' on the baord. After doing some digging this looks like it could be for an oscilator to provide the clock signal for the CPU?

There may be other parts missing too. Of course it's possible the board is completely dead and that's why it has been harvested for parts, but unless I replace that 'X1' part then it's never going to work. I was hoping someone might be able to either take a snap of the PCB, post a schematic (I've tried searching for these but to no avail) or simply pop the lid off their Capcom IO and post up the part number.

Oh and I have no idea which revision of the board mine is. I believe there are two revisions. I'll try to post up a pic later.

Thanks.

[Sp33dFr34k]

Clicky.

Looks like a 14.7456 mhz crystal to me.

[Madbury]

Awesome thank you that is super helpful.

[Sp33dFr34k]

You're welcome, hope you can get it to work again

[Madbury]

For reference, below is a pic of what I'm starting with. Looks like the board is a different version, but the layout is similar.

Parts I've ordered
1 x 14.7456MHz 20pF
3 x PS2801-4-A
1 x ADM485JRZ - looks like this is incorrectly labelled on the PCB as ADM458JR

My Capcom IO board
pic of my Capcom IO board