SFX4000: WIP PCB to adapt an SFX power supply to fit inside the NVS4000

[zetsurin]

HI all,

This is my first foray into PCBs and using KiCad, but I have made up a PCB designed to fit inside the NVS 4000 enclosure allowing the aging power supply to be replaced by a new SFX power supply, while retaining the original appearance. I was driven to this after recapping a PSU only to find out it's definitely not the caps etc. It's currently a work in progress and it's very much a DIY project since the 90 degree AMP UP connectors themselves need to be de-soldered from the original and resoldered. I've stuck with the original types of connectors that were originally used in these arcades, perhaps for a bit of authenticity but they are still fairly easy to track down for now.

Basically:

- Right angle ATX header (later changed to straight header as it's a tight squeeze)
- Replace rear fan with 80x80x10mm fan to further save space.
- 3 pin 90 degree AMP connector for power
- 2 pin right angle JST XH for fan header
- Straight 7 pin JST HX for test/service/jamma audio.
- Optionally: A negatron.
- 5mm 12V red LED
- approx 300 Ohm or so resistor if one isn't built into the LED.

I can grab all the parts and links to digikey shortly.

Not sure if it's useful to anyone as it's a pretty niche situation, but in case it's useful I thought I would share what I made so far. I had a first run made and it all seemed to measure up fine in place in the NVS4000, and have just revised it to optionally take a Negatron to add -5V.

Since I am really learning about PCB layout, any feedback would be appreciated. And if anyone is thinking of getting boards made, please wait until I get the next batch back to test first.

 

[zetsurin]

Just to follow up on this, my board is fully assembled. Adds -5v via the negatron which you normally won’t get with the nvs4000. Now i can run fussy boards like mortal kombat with no tuning required. From the outside you would be none the wiser. Its s niche use case but one i was personally looking for so just sharing in the off chance anyone else ever needs it.

 

[Hackcell]

I'd buy one of these boards, for sure! The option of having -5VDC is something awesome!

 

[Hackcell]

Hello,

I was checking your design and there is room for a few suggestions.

1 - Add the 3 AC ground pins, as it seems the original PSU has.

2- Also, are you sure you are taking +5VDC for the negatron? it seems to me you are using 12 VDC instead.

Just trying to understand and to help

 

[zetsurin]

Hi Hackcell, yeah routing the frame ground through to the middle of the AC outputs would be handy. I guess it would just need to run across the top side of the PCB to not disturb the AC lines.

As for the -5V I am indeed taking this from 12V and it's entirely intentional, as if you feed 5V in to derive the -5V using the negation the max current it can handle is only 180mA, but deriving -5V from 12V will allow for 500mA max current.