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.