Jamma harness ground connections?

[kingtreelo]

Hi, so i need to tie all my ground connections together on my jamma harness and other than running a little wire, is there an easier way to do this?

I would guess there is a connector that you can put one ground wire in that bridges the 2/4 pins?

Does something like that exist, and if so, what is it called?

 

[John Bennett]

The idea really is to have separate cables back to the PSU for every ground pin, and in the same way have separate cables for every 5V, 12V and -5V pin.
This reduces the voltage drop across the cables.
Otherwise you risk different voltages being applied to different games, depending on their power draw, unless you're going to twiddle the PSU dial every time.

 

[favouredson]

As JB stated, the more the merrier.
If your cabinet loom is properly wired it will also make up for deficiencies in any JAMMA adaptors you might use.

 

[kingtreelo]

i'll take a look, there arent any loose wires from the wiring loom that i can see, but TBH, i havent really looked that much

 

[kingtreelo]

so ive had a look today and cant see any spare wires at all to hook up to the harness, i was expecting to see a few ground wires on the loom that were loose but nothing...

any ideas?

 

[favouredson]

Ideally, you would add wires from the PSU to the connector.
If you are unable/unwilling to do this then you could always do a bodge and make up a JAMMA to JAMMA adaptor with all the ground pins interconnected.

 

[kingtreelo]

Ideally, you would add wires from the PSU to the connector.
If you are unable/unwilling to do this then you could always do a bodge and make up a JAMMA to JAMMA adaptor with all the ground pins interconnected.

could i not just connect the grounds that are already wired to the other pins?

im not even 100% this is going to fix my problem but its worth a shot

 

[BigP_BigP]

could i not just connect the grounds that are already wired to the other pins?

im not even 100% this is going to fix my problem but its worth a shot

Totally agree with all the above posts. Commonly grounding issues stem from poor quality wire (too little copper). This is a particular issue on some of the eBay/Aliexpress JAMMA harnesses. I restored(?) a Chinese clone blast city a year or so ago to make a dedicated DDPDOJ cabinet. In doing this I had to totally remove the gnd and 5v wires (apart from the thinner button grounds) and upgrade the wire thickness to 16awg. Typically the cheaper harnesses look like 18awg but when you cut the wire it only has the copper of a 20-24awg wire the thickness comes from the shielding. Something similar may help in this situation. (Excuse the cab pic post... any excuse)