Computer Space Repair Thread

ComputerSpace

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Hello all,

I had posted some CS power supply questions in a different thread, which is here...

http://forums.arcade-museum.com/showthread.php?t=255066

Ok, since I've replaced the original power supply with a switcher I thought I had better put this in a new thread. I have the game working in demo mode but there are some other issues with it now. So, I've started this thread for any other CS owners that might be having issues with their game.

I started by measuring the voltage out of the original power supply and it was putting out about 6.00 vts instead of 5.00vts. Also, if I read my meter right I saw about 12vts of AC ripple in the out put of the original supply. At that point I decided to replace it with a switcher.

I cleaned up the butchered wiring, then installed the new power supply. I uninstalled the original PS just so I could have some room to work in but I'm not getting rid of it for the purists. At that point I tested the voltages w/o the game boards connected. I set the voltage to 5.05 volts then turned it off.

I forgot to mention that before all of this I ordered off of ebay and installed all new tubes into the TV just for good measure since it's about 40 years old by now...

Now I connected up the TV to see what I could see with it, before I connected up the game boards. I expected to see a bright, gray screen, but didn't see anything. I connected up the game board connector and after the monitor warmed up I had a messed up picture.

After spending over a half an hour working with the TV controls I was able to get it tuned in and see a great clear picture. The controls were way out of alignment. So at this point I have a great attract mode picture, but will the game play. I switched off and connected the control panel. Power up, no lights on the control panel. Wiggleing the control panel caused the coin counter to click. Wiggleing it more, caused the control panel to light up.

Obviously a loose connection somewhere.

That is where I've left it. It will start a game, I can hear faint sounds though the speaker but the monitor flips out when a game is started. When the game is over, the monitor displays a perfect attract mode picture.

Here are some pictures, but I don't have one of the flipped out picture. I'll get one of those later. I'm guessing I have a problem with the star/sync board. I'll post more about why I think that later...

Tom
 

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That is one good looking pic of that game. I am fairly certain the issue is with the monitor and I would invite a monitor guy to weigh in on this issue.

I am glad to see one of the first games still working and will help in any way I can.
 
You know, I think this is the first one of these repair threads I've ever seen for Computer Space.

I'm sure there just aren't enough of them around to generate the traffic; pretty cool to see!
 
You know, I think this is the first one of these repair threads I've ever seen for Computer Space.

I'm sure there just aren't enough of them around to generate the traffic; pretty cool to see!

I am fairly certain it is a monitor issue and have ask a good one to weigh in on this.
 
I have only had my Computer Space for a very short time but if the 5v isn't right on I would get no picture, or my ship would not shoot, or the picture would fade in and out. Once I got it perfect the game worked great, mine has the original power supply. The original power supply looks pretty basic I would suggest you rebuild it. Also do you have a link to where you bought the tubes or did you get each one from a different seller?

Good luck, sorry I'm not more help
 
The thing I don't get is that it is working until you start a game, when things start moving ib the tube. Then the picture starts to get 'jumpy'. Not much of a help right now but a bump for the work week crew to see this issue.
 
A short update here...

Last night I pulled the control panel connector apart looking for any loose or broken solder joints due to the coin counter jumping while wiggling the plug. Everything looked good in there. Now down to the computer box, all of the solder joints look good there, but the pins are kind of loose in the plug. This is a real old style connector with flat blade pins in it. I'll deal with that later since I can get the control panel to work by wiggling the plug to just the right spot. Might just need to be cleaned.?

I pulled out all of the boards and cleaned the edge connectors. The boards appear to have been worked on as recent as last March and April (stickers on them). I've read that you can power up the game on last board in the stack - I believe it to be the star / sync board and should get a star background so I gave that a try. The monitor displayed the same screwed up picture I get when I coin up and try to play a game. Interesting. Power down and installed the other two boards. Powered up and had a perfect attract mode picture again.

I'm thinking I may have an issue with that 3rd board in the stack. I'll take a pic or two of the screen and post it as soon as I can.

Tom
 
A short update here...

Last night I pulled the control panel connector apart looking for any loose or broken solder joints due to the coin counter jumping while wiggling the plug. Everything looked good in there. Now down to the computer box, all of the solder joints look good there, but the pins are kind of loose in the plug. This is a real old style connector with flat blade pins in it. I'll deal with that later since I can get the control panel to work by wiggling the plug to just the right spot. Might just need to be cleaned.?

I pulled out all of the boards and cleaned the edge connectors. The boards appear to have been worked on as recent as last March and April (stickers on them). I've read that you can power up the game on last board in the stack - I believe it to be the star / sync board and should get a star background so I gave that a try. The monitor displayed the same screwed up picture I get when I coin up and try to play a game. Interesting. Power down and installed the other two boards. Powered up and had a perfect attract mode picture again.

I'm thinking I may have an issue with that 3rd board in the stack. I'll take a pic or two of the screen and post it as soon as I can.

Tom

It can also be the connections to the boards is intermittent (from one board to the other(s)).
 
I have only had my Computer Space for a very short time but if the 5v isn't right on I would get no picture, or my ship would not shoot, or the picture would fade in and out. Once I got it perfect the game worked great, mine has the original power supply. The original power supply looks pretty basic I would suggest you rebuild it. Also do you have a link to where you bought the tubes or did you get each one from a different seller?

Good luck, sorry I'm not more help


Braido, I was able to locate all but one of the tubes from this seller on ebay:

heschmidt732vca

Good prices, great packing and fast shipping. I just searched around for each tube then when I found some hits I started searching their stores for more tubes. This guy had them all but one so shipping was reasonable. I didn't want to pay more the ship the tube than the tube cost.

Tom
 
I'm sure that TV is fulla dried out caps. I'd replace every lytic in it and if there's PC boards, check those all out for cracked solder. Since this is a tube based TV, its especially important to have fresh caps in the HV supply for the tube plates. They don't age well ('specially when sitting idle for years on end) and get is such a condition that they will get (electrically) leaky and draw current on thier own....stressing or wrecking the pwr transformer.

Oddball TV tubes are *everywhere*....not hard to find for chump change.
 
If the edge connector looks like this:

124731.jpg


chances are the pins are bent/worn and need to be replaced. If you're attempting to keep this all original, you CAN still buy the pins, they're this: http://www.moogmodular.com/tyco_duo-tyne.pdf

This is the same connector Midway uses on a bunch of games like Sea Wolf and Space Invaders. Most people replace them with the molex equivalent thats more reliable/modern.

I agree on the sync board being an issue; chances are a counter chip (161) somewhere on that board is bad causing the sync to go nuts when a game is started. With a perfect attract picture I highly doubt the TV the problem.

(PS I too think a Computer Space thread is just cool :))
 
Got the picture of the edge connector, they do not look like those. They look more like the early Atari B/W edge connectors.

I'll try to get some video of what's it's doing today and post. Keep the thoughts coming...

Tom
 
Question...how is the tv hooked up? I watched the video on an actual computer and I think I know whats going on...the audio and video signals are mixed....you can "see" the sound signals and hear the video signal.

Id look at the wiring first, then if possible try to hook up a known good tv (any should do). If the problem still happens then Id look into how the sound is generated or try turning the volume all the way down...almost wondering if the speaker is vibrating the boards and causing that due to bad connections.
 
Computer Space is working!

Thanks to a CS expert, I followed his suggestions and was able to get CS back working again.

Basically, it was bad / dirty connections in the edge connector area. I have one word for anyone trying to fix weird symptoms like this...DeOxIt spray. That stuff is miracle in a can.

Pulled the cards from the cage, sprayed the edge connectors, the boards edge connectors, the jones connectors. I found a couple pins in the edge connectors that were compressed and kind of bent them back into a position what would, hopefully, allow contact. Put it all together and tested...Worked!

Here's a couple videos of it playing now. Yes, I suck at game play but I'm getting better...


A short one in hyperspace mode (extended play):



Thanks for all the input and let's continue to use this thread for any other CS issues anyone would like to post, and their solutions.

Tom
 
I am glad you got yours working. I am going to see if I can get a set of tubes also. Did you have the list of tubes you could send Braido and myself privately? I have a CS with a minor sync issue myself.

Michael
 
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