Jesse69
New member
I got kinda lucky buying a Stargate Defender for $330, - it was listed on ebay for $400 or Make Offer. The seller, Scott, said he'd take my offer of $330 and I drive from Chicago to Detroit to pick it up [$72 gas R/T]. When I got there by GPS to his house I only did a quick game test and the machine seemed fine. But later when I got it in my house it would reset on the game. I couldn't break 300,000 before it would reset.
Initially going through all the diagnostic tests it would say no ROM or RAM errors. The I won a ROM board on ebay [untested] for $20 and it worked fine but the Stargate still reset. Then I won another complete ebay Stargate PCB / Power Supply board set and I tested everything and I got another good ROM and Interface board. The main CPU Video board has bad RAM because on startup it says "book keeping error, close door to reset ram" or something. The spare sound board is faulty and doesn't produce all sounds "on the dot." So I'll have these spare boards repaired by the guy who advertises on ebay that he does Stargate PCB Repairs.
Now my initial original Stargate Main CPU / Video PCB RAM finally went bad. Funny how the game still runs on bad RAM. At startup it says "ALL Systems Go." But I did the RAM diagnostic test several times and got "RAM 35," "Ram 32," and "RAM 31" errors. What do these mean?
Just ordered 120 4116 RAM chips and can't wait to get them. Will replace all 24 RAMS on my original and spare MAIN PCB boards. Hopefully that fixes all the problems!
Oh, but after I clean my original Main PCB at all contacts with a wet tootbrush, and fixed a broken trace at the backside of the board with CircuitWriter - my game reset less even with bad RAM and I got a high score of 395,000 + 2 other 300,000+ games. So now there's no chance of chip shorting between pins due to corrosion or dirty contacts.
In the end, I want a perfect running Stargate so I can break a million on it. I broke a million in Defender back in the 80's but not on Stargate. Stargate would just suck up my quarters.
But I cheat a little on my Stargate - I set Inviso to 2 sec per ship rather than the std 1 sec per ship.
And the seller Scott put a switching power supply in it and I found the best voltage to set the +5V was at +5.41V so the main board gets +5.33V and the Rom board get +5.25V. Seems to reset less at that voltage.
Any comments or advice?
Initially going through all the diagnostic tests it would say no ROM or RAM errors. The I won a ROM board on ebay [untested] for $20 and it worked fine but the Stargate still reset. Then I won another complete ebay Stargate PCB / Power Supply board set and I tested everything and I got another good ROM and Interface board. The main CPU Video board has bad RAM because on startup it says "book keeping error, close door to reset ram" or something. The spare sound board is faulty and doesn't produce all sounds "on the dot." So I'll have these spare boards repaired by the guy who advertises on ebay that he does Stargate PCB Repairs.
Now my initial original Stargate Main CPU / Video PCB RAM finally went bad. Funny how the game still runs on bad RAM. At startup it says "ALL Systems Go." But I did the RAM diagnostic test several times and got "RAM 35," "Ram 32," and "RAM 31" errors. What do these mean?
Just ordered 120 4116 RAM chips and can't wait to get them. Will replace all 24 RAMS on my original and spare MAIN PCB boards. Hopefully that fixes all the problems!
Oh, but after I clean my original Main PCB at all contacts with a wet tootbrush, and fixed a broken trace at the backside of the board with CircuitWriter - my game reset less even with bad RAM and I got a high score of 395,000 + 2 other 300,000+ games. So now there's no chance of chip shorting between pins due to corrosion or dirty contacts.
In the end, I want a perfect running Stargate so I can break a million on it. I broke a million in Defender back in the 80's but not on Stargate. Stargate would just suck up my quarters.
But I cheat a little on my Stargate - I set Inviso to 2 sec per ship rather than the std 1 sec per ship.
And the seller Scott put a switching power supply in it and I found the best voltage to set the +5V was at +5.41V so the main board gets +5.33V and the Rom board get +5.25V. Seems to reset less at that voltage.
Any comments or advice?
