Hi all, I'm new to the board. After doing some googling and research, this looked like a cool place to join and participate. My really short introduction... I've been repairing hardware of every kind since 1981. For almost 20 years it was a full time job, but these days I do networks and databases. I still do repair work for fun, hobby, friends and "beer money" though. One day might be a flat panel, another an engine timing belt, the next is a commodore 64, then an 8 track player..... You never know what I might be into next.
Today I bring with me a battered Williams Defender cabinet with a Stargate upgrade and marquee installed that I'm slowing restoring. I've repaired the power supply, the monitor (though it still may have and issue) and managed to get enough life back in the motherboard for it to show a memory error of 1-3-1 continuously, and it appears to be doing and endless rug test. I pretty sure it's not a memory chip problem though. (keep reading below). When I started on this it was in bad shape. Tthere were no error codes at all and just steady signals in most places.
See a screen video here and you might tell me what it's up to as it tries to boot....
http://s544.photobucket.com/albums/hh331/PlazinJavelin/Arkanoid/?action=view¤t=StarGateRug.flv
The cabinet itself is also going to need work, but I'm a handy work worker too.
I find it hard to imagine this poor thing ever worked at all. When I recieved it, it was in such rough shape that I concidered MAME-ing it. But it was very complete and I hate it when original equipment gets hacked up, so I decided to put it all back together. The motherboard has been the most challenging repair for me in a long while. Here's what I've done so far....
1) Converted the 4116 ram to 4164. Once I found that at least 4 of the 4116's where bad, it seemed to make more sence to go 4164's than to try and find more 4116's and wait for the next ones to go bad.
2) Tracked down and replaced 3 other bad IC's. Going by the CPU assembly drawing these are in locations 5E,6E, and 6F. Each of these were giving horrid logic levels causing havoc on the rest of the board. With new replacements in, signals every where look good and the system now displays the ram error and apparent rug patteren. But from the looks of the video, either the sync signals are shot or the monitor needs more attention. I'm not sure yet if this is because of logic from the motherboard or if the monitor still has another issue. I'm leaning towards sync signals ATM.
3) Read through this thread to see if there were any more clues to the problem.....
http://forums.arcade-museum.com/showthread.php?t=88194
4) All the memory has good logic levels and the chips were testing working in another peice of equipment.
Though the system is showing the memory code, I'm guessing I'm looking for some other issue. I've repaired a few dozen cabinets over the years (most recently Space Invaders and Arkaniod) but this is the first Williams I think I've seen. Any input to help speed this restoration along would be appreciated.
Plaz
Today I bring with me a battered Williams Defender cabinet with a Stargate upgrade and marquee installed that I'm slowing restoring. I've repaired the power supply, the monitor (though it still may have and issue) and managed to get enough life back in the motherboard for it to show a memory error of 1-3-1 continuously, and it appears to be doing and endless rug test. I pretty sure it's not a memory chip problem though. (keep reading below). When I started on this it was in bad shape. Tthere were no error codes at all and just steady signals in most places.
See a screen video here and you might tell me what it's up to as it tries to boot....
http://s544.photobucket.com/albums/hh331/PlazinJavelin/Arkanoid/?action=view¤t=StarGateRug.flv
The cabinet itself is also going to need work, but I'm a handy work worker too.
1) Converted the 4116 ram to 4164. Once I found that at least 4 of the 4116's where bad, it seemed to make more sence to go 4164's than to try and find more 4116's and wait for the next ones to go bad.
2) Tracked down and replaced 3 other bad IC's. Going by the CPU assembly drawing these are in locations 5E,6E, and 6F. Each of these were giving horrid logic levels causing havoc on the rest of the board. With new replacements in, signals every where look good and the system now displays the ram error and apparent rug patteren. But from the looks of the video, either the sync signals are shot or the monitor needs more attention. I'm not sure yet if this is because of logic from the motherboard or if the monitor still has another issue. I'm leaning towards sync signals ATM.
3) Read through this thread to see if there were any more clues to the problem.....
http://forums.arcade-museum.com/showthread.php?t=88194
4) All the memory has good logic levels and the chips were testing working in another peice of equipment.
Though the system is showing the memory code, I'm guessing I'm looking for some other issue. I've repaired a few dozen cabinets over the years (most recently Space Invaders and Arkaniod) but this is the first Williams I think I've seen. Any input to help speed this restoration along would be appreciated.
Plaz