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Computer Space Monitor Repair and info


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#1 Cassidy Nolen OFFLINE  

Cassidy Nolen

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Posted Sun Jul 20, 2008 12:11 PM

ComputerSpaceFan, feel free to copy this to your website. PM me and I will give you a word version of it…..


For those souls who keep the embers alive on the bronze age classics, I have a tale to tell.

After 8 years of ownership, my Computer Space 2 Player is going to a new home. It will be a home equal (likely better) than I to appreciate its splendor and significance in the game timeline. I have done some repairs to get it ready for its journey. To understand Nutting games is to know that tinkering is constant and “working” is a term best used to describe a game one day rather than in general. In other words, it’s a sports car that at best is tempermental. When I fired it up a few weeks back I noticed a tick associated with the flyback on the television. Remember, this game uses a tube-type television (vacuum tubes, that is) for a monitor. Turned out the tick was an internal short across the secondary windings of the flyback itself. Great. I knew what was wrong but it’s not exactly easy to find the part somewhere at Best Buy. Research ensued. Here is what I found.

The original television GE model was called a Venturer III. This hybrid television used transistors and vacuum tubes together on one single chassis. Very cool, very easy to work on, odd in the annals of tele history. http://www.rwhirled....color/GE-SF.htm is a site that covers the details. At least now I know what I needed to hunt down.



By the way,
http://s88.photobuck.....mputer Space/ is my photo hunt as I progressed if you are interested…

So I had a radio newsgroup guide me to find that the chassis type in the television is the part I needed to focus on. The chassis is called a “SF” chassis. Perfect. So theoretically, I needed a flyback for a GE SF chassis. As I learned, GE television parts are not desired like the RCA counterparts so nobody kept them. On a suggestion from the radio forum, I began to hunt down a fully working television to get the parts from. The chassis I have in the game is a S-2 version but I was assuming that any SF chassis had more or less the same layout. Here comes the ebay part…

I found this television on ebay for 10 bucks (see the picture at the bottom of this post). For a while, you can see the auction if you search Auction number 320198768504 . Working but not able to get in a channel, it seemed like the perfect donor, if stuff was close enough to fit. It’s a 9 inch screen, hence the SF-9 model number. My game is a SF-15 (I am guessing for the 15 inch tube) Emailed the seller (turns out to be a great guy) and took some internal pics of the game. I saw the flybacks looked similar so I was in. The blue one on the right is the original, the white one is the 9 inch set flyback. Same identical size and footprint, only in MUCH better shape!

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Fast forward to disassembly day, and you are good to go. The flyback is a straightforward swap, with two wires that connect to the rear most vacuum tube. They were tricky to remove but not impossible. Turns out the game worked great with the replacemet flyback. Could not be happier.
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So in closing, Computer Space (one and two player version) used a GE SF based television. The units are interchangeable to a large extent with any SF chassis based television. Rather than trying to hunt down a complete tube set, I would suggest finding a working SF based television and doing some swapping around. This tv is available and identifiable by its numbers on the back. From what I have seen, the actual model number is not as important as that chassis is. The SF chassis version 2 has a separate audio driver board that Computer Space accesses directly. The version 3 that I bought on ebay is missing that board and I have not gone further to find out where they relocated it in the system. Would not be that hard, I just don’t care enough.

Keep the old ones running if you can. Hopefully this will help somebody save some time.


Cassidy

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#2 Cassidy Nolen OFFLINE  

Cassidy Nolen

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Posted Wed Jul 23, 2008 3:31 PM

I am guessing this is not "hot arcade repair info" for the average gamer :) but I figured I would add the following for future searchers looking to mod that tv from ebay.....

On an SF chassis, WITH the audio card:

Black wire from Computer Space goes to pin 9 on the audio card
White Wire from CS goes to pin 8
Red wire from CS goes to terminal pin 11 of the vacuum tube 15BD11


This is all assuming you have cut the white RF cable that runs between the tuner section on the monitor and the actual chassis. That disables the tuner section and allows the pin 11 to carry all your video and the pin 9 on the audio card to handle sound. The pin 8 is a shared ground.


Again, I am not thinking this is common need info but maybe this will save somebody the month it took me to compile it all :)
(honestly, probably help me out sometime rather than have to find whatever I wrote down somewhere).

Cheers,
Cassidy




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