My wife was going through Craigslist a few weeks ago, when she came across a Space Invaders game.  She asked me what I thought about getting it.  The price was right so I said sure!

We went out and picked it up.  It was in good condition with the original 1970s graphics intact.  We got it home and I started poking around in it.

My full time job has me working in a bowling center.  Maintaining the games in the arcade is part of my job, but arcade games today are not the video games of my youth!  THIS was a game from my youth, and it looked it when I opened it up.  It runs on an old 8080 processor, and a few other smaller boards for the power and sound.  After a few minutes with the game, I noticed that the manual that came with this game was for Space Invaders II – with different hardware and software.

My experiences at work made it clear that the manual for solid state equipment has to be followed to the letter, unless you know as much about the game as the person who originally designed it.  So far, my only experience with repairing solid state equipment goes back to my Bally Eight Ball game which needed a replacement light driver board, and then later required a new diode on that same board.  As for tracing logic paths, etc., I have no experience in that department.  So, I knew enough to know that the wrong manual won’t get me where I want to be.

I made contact with a guy who had a copy of the manual I needed.  A week later, manual in hand, I set out to try to bring Space Invaders to life.  I decided to replace the fuses first.  One was toast, and the other one seemed good, but I wasn’t sure it was the right one.  Manual in hand, I hit the local Radio Shack and grabbed what I needed.

I replaced the fuses with new ones, exactly as specified in the manual.  The power cord had been cut.  Not having a replacement on hand, I used butt connectors to reattach the severed wire.  I checked for voltages with my multimeter and seemed to be getting the right kind of power.  The blower fan came on, and the screen seemed to work, but nothing else seemed to happen.

I killed to power and tried a few different things, but to no avail.  My brother-in-law and his wife were coming over to visit us that afternoon.  I was hoping to have it running by the time they came over, but it wasn’t looking too good.  When they arrived, I shut everything down and went to greet our guests.

Upstairs, the conversation finally swung around toward Space Invaders.  We talked about the game for a bit, and finally we all went down to take a look at it.  My wife’s brother is a whiz with computers.  He built us a computer once and created a program for us to use in a business once.  He was curious to see a game that was as old as he was!  After us all having a laugh about how old everything looked inside the game, we set out to trying to figure out how the boards all worked inside the game.  We identified all of the parts in the game, and identified all of the connectors.  I gently pulled each connector apart to inspect it and make sure it fit snugly.  Then we figured out which connector had the wires to supply the motherboard with 5 volts of power.  I pulled the connector apart, and found that one of the pins was almost jet black, and it was the 5v power supply!  I went into my toolbox and grabbed some 600 sand paper and gently cleaned up the pin. 

Then we turned on the game.  Since there’s no hard drive on the game, it didn’t sound any different when it started up, but then someone noticed text appearing on the screen!  It was blurry at first, but as the monocbrome CRT screen warmed up, the images became crisper.  We put in some credits, and pressed the start button – the game played flawlessly! 

Now, over a week later, Space Invaders is a big hit in a house of mostly pinball fans!  I’m hoping to restore the game to it’s original conditon, but maybe not right away.  For the time being, I think I’m just going to enjoy it as is!