Overhauling the Sega Astro City – Part 11, rewiring the cabinet

Posted Wednesday, 25th May 2011 under Arcade cabinets
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This one is best told in pictures. Let’s start with the before:

Looking inside the cabinet from the outside:

Closer up:

Power supply in focus this time:

Molex connections galore:

And the AC wiring, complete with heatshrink tubing and solder for the spliced connections:

Here’s the aftermath, with all the control panel wiring intact (since it will be reused), and all the excess wiring removed:

And for the sake of completeness, here’s the control panel without the bracket that houses all the molex connectors:

Now that all the wiring is out, next came the step of stripping everything out of the cab – the outer layers were removed that hold the bezel and speakers, exposing the fluro tube, and the monitor in its entirety (cage included) was also removed. To open up the insides for working, I also removed the partition that holds the PCB holder and separates the two halves of the cab. It really is looking like a shell now.

So, let’s start the refit – here’s a shot of the inside of the cab with only the new AC wiring present, with everything terminating to a female socket for ease of use:

Next up, add the step-down transformer to the partition to the right:

Add the partition to the cab and mount the SUN PSU into place; it’s positioned to allow for thick PCB boards, the MAME PCB or CPS2 setups, but still retain access to the unit for adjusting DC voltages:

… and another shot:

This next show shows the control box and the power board attached to the side of the cabinet:

The following closeups demonstrate when the control box and power board sit:

… and another:

… and another one:

Almost there – the JAMMA harness has been added, molex connections are complete and cable-tied close to the frame, JAMMA harness is hooked up and some RCA connections have been added for the output on the control box:

And there we go – all finished and much neater than before!

That takes care of the cabinet, but what about the control panel? We can’t forget that! Here’s a shot with the amp installed with all the wiring to the speakers and control box completed and the bracket re-installed:

And here’s the final shot with extra earth wiring grounding the monitor frame, amp, bracket and the coin slot chute/coin box:

Bit of a marathon run, but it came out really well. Next up – the new monitor!

As noted before, posts on the refurb are being done ad-hoc, so to keep track of the whole project, just use the Sega Astro City Overhaul tag, as the whole series will be added to it over time.

Overhauling the Sega Astro City – Part 2, audio amplification and fans

Posted Wednesday, 28th July 2010 under Arcade cabinets
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I’ve already got the ball rolling in part 1 of this series, so let’s move on to part 2 – audio amplification and fans.

In line with the previous post, I want to add a way to have a stereo amp in the cabinet to take care of line-level sources and enhanced stereo sound (e.g. Naomi, CPS-II, Sega Model 3, etc). So, in the spirit of making the cab as universal as possible, I need to look at adding in a small amp that can be switched on or off as required, and be able to direct either amplified sound off the JAMMA cable or amplified stereo output as required. So, this is what I’ve come up with:

It’s not all the difficult – I’ll need to rewire the 4-pin connector that goes from the speakers at the top of the cab so that they’re separated into stereo channels, then create a little switch to roll between a split dual-mono amplified output (from the JAMMA harness) or stereo output from the stereo amp, which in turn is powered off a 12v source (with switch to control when it’s on) and grabs its input directly from the PCB (Naomi, Model 2, etc).

This then means the audio can be setup in the cab when inserting a new board. All I’ll need are a pair of stereo RCA cables to run form the CPS-II or Naomi boards (and make a stereo RCA adapter for the Model 2/Model 3 boards) and run them off a pair of 12v mono amps I already have around the place, and I should be good to go.

The other addition I’d like to add is a stereo controller I can mount on the cab to adjust the output before it goes to the speakers as required – there’s currently a cheap knob the previous op added to give this kind of functionality, but it’s not a true stereo actuator, and doesn’t do much except distort the audio 😛

Of course, the great thing with this setup is that it won’t cost much at all to add this kind of functionality. To make it clean though, I’ll plonk the lot into a small project box and mount everything inside it. This way, I can use the same project box to run a 12v switch to selectively power the 12v fan I got with my Model 3 kit before. And to make sure I don’t mangle my hand again, I’ll also grab a pair of 120mm fan guards to avoid any more stupidity 🙂

Thus ends part 2 – part 3 will deal with the lovely scope creep and deciding what to do with my monitor 😀

To keep track of the whole project, just use the Sega Astro City Overhaul tag – the whole series will be added to it over time.