Neo Geo Cabinet Power Supply Overhaul

We’ve moved on a little bit now on the Neo Geo cabinet project, the first step to take was to sort out the power supply module.

Electrocoin Golaith’s have a power chassis comprising an isolation transformer, switch mode PSU, an isolation switch, mains AC filter and fuses.  The one that came in the cab had been hacked out – the switch mode PSU was not present, the fuse holders had been put in wrong and the wiring wasn’t right.  Here’s what it looked at before:

So, the first thing to do was order a bunch of parts:

Pictured above is a bunch of AMP mate’n'lok connectors, pins, JAMMA fingerboards, edge connectors, de-soldering braid, solder, new soldering iron tip cleaner, arcade switch mode PSU’s (need one to replace in another machine) and various other connectors that’ll be needed.

So, work carried out on the PSU to make it usable again:

Trace and rewire the mains input through the filter, cherry switch to the fuse inputs.  De-solder the fuse connectors and remove and replace them correctly (they were being held in by the fuse holder rather than the flange around the barrel so weren’t making contact properly anyway).  Replaced all three fuses as a matter of course.  Replace a cut wire coming from the isolation transformer to the fuse.  Make a 6-pin mate’n'lok to a Hantarex 9110 power connector for the monitor.  Fit the switch mode PSU and ensure all earths are nice and snug.

Here’s the finished PSU:

At the lower right is a test-connector using a 3-pin mate’n'lok – on the Goliath cabinet the power is routed up to a switch on the top of the unit and then back to the power supply board.  The interlock switch has to be depressed by the back cover (or pulled out by the engineer) in order to let power flow through and for some reason, Electrocoin went a bit over the top and put fuses on both the live and neutral lines.

After testing, the isolation transformer is delivering 135volts AC which the monitor will use, 250v which will go to the marquee light and to the switch mode supply and that in turn is putting out a nice steady +5v, +12v and -5v all DC.

Job 1 done!

Next up is to get the monitor going, i’ve got a nice 25 inch tube I was given and the correct chassis for it but it’ll need a bit of tinkering to make it work properly.

Building A Neo Geo Cabinet

After seeing some nifty videos on YouTube from johnsarcade.com with the games he had in his games room, I decided i’d quite like a Neo Geo system too.  The system is fairly straight forward, you get a motherboard – they come in 1, 2, 4 or 6 slot versions, they are JAMMA wired but use some unused pins for the fourth button for each player and a select button for which game (if using a multi cartridge board) and hook up to a regular arcade monitor.

First job was to get hold of a motherboard – which one though?  I did some reading on jammaplus.co.uk as well as this guide from Arcade Otaku’s wiki and found that the 1 slot is the most reliable and the 6 slot is the most unreliable, I got to thinking about whether i’d want multiple games.

Of course, the answer to that was YES!  The whole point would be to be able to switch games quickly and I really wanted something like how johnsarcade.com has his with 4 slots and the marquee lights up for which slot is in play.  So I decided to go for a 4.

Why a 4?  Well, simple….. because! OK!  No, seriously, I could just swap the cartridges as a need for changing games happens but its so much more fun to have multiple cartridges – I can swap JAMMA game boards in my cabinets easy enough but when people come round they just see whats playing and never ask what else you have even though there’s a growing stack of PCB’s on the shelf.  So this will be a nice, player friendly addition to the games room.

As luck would have it, I found one going quite cheap on eBay but the postage was a bit outrageous, fortunately, I was over that way picking up a Defender machine from a friend so I contacted the seller and did the deal and picked up the board motherboard.

Below you can see a picture of it set up on my Vogatek Supergun MK5 on a regular 26″ LCD with a couple of games in it.  I can’t get a select button working but I think that’s more to do with where it is wired up on the edge connector rather than the motherboard.

4 Slot Neo Geo motherboard tested and working

There’s a bunch of things to do before I can get this into the games room, one of which is get hold of Puzzle Bobble and League Bowling which were my two favourites back in the arcade days of glory – I just never knew they were Neo Geo because the arcade obviously had them on a single slot board.

I need to:

• Find a connector for the remote adjustment board for a Hantarex MTC9110 chassis to go with the 25 inch tube I have.  The chasis works, it just needs the adjustment board plugging in properly.
• Clean up the Goliath MK3 that it is destined for – it needs a new loom, marquee light (well, 4 lamps actually), side art etc
• Control panel rebuilding or drilling – the MK3 has a bare control panel but needs sorting out and a bit of re-welding doing and then recovering.  I have a NEO GEO control panel that was donated to me, I wonder if it will fit the cabinet – watch this space.
• Get new or reproduction Goliath MK3 glass for the cabinet
• Physically mount the motherboard for the neo geo with clearance for changing cartridges.
• Wire up the select game switch and marquee lights etc.

Should take me a month or two and i’ll try and post updates regularly – watch this space!