Resurrecting a Stargate/Defender Cabinet

Plaz

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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&current=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
 
Oh, one more thing.... are the rom binaries available for these. I probably need to verify all the roms and the decoders still have all their bits.

Plaz
 
A little more information please, about your conversion from Defender to Stargate:

1) When you did the 4164 upgrade, did you do the connector modification that is required also? The 4164s do not use the same voltage inputs as the 4116s, and using them without a modification to remove the -5 and +12 power inputs to the CPU board will cause them to fail.

2) Did you replace all the boards as part of your conversion? The Defender CPU is different from the Stargate CPU, and they will not work together. I think the Widget PCB is different, too, as well as the ROM board.

3) What's your +5 reading at the RAM chips? Usually the 1-3-1 error is indicative of a problem with the power.

4) I'd also check the status of your ribbon cables between the CPU and the widget/ROM boards, as they can cause problems as well....
 
you should buy from member jrok his 19 in 1 and put that in the defender cab. it has 19 games like defender, stargate, joust, sinistar, bubbles, uhhh i cant remeber all them right now but it rocks! you will have to add a joystick to the CP and a button for inviso.
 
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1) When you did the 4164 upgrade, did you do the connector modification that is required

Yes the connector is modded to eliminate 12v and supply 5v to the proper pin for the 4164. I also pulled out pin one of each chip to bypass -5v

2) Did you replace all the boards as part of your conversion?

The previous owner bought this years ago as a working Stargate cabinet and presented to me as Stargate. I don't think he ever knew the difference, and I didn't realize it was a Defender cabinet that had been converted until I got it home and opened it up. I haven't checked the version numbers specifically on the sound board, but the rom board and motherboard are correct. Should I be looking at any other version numbers?

3) What's your +5 reading at the RAM chips?

~4.9, I'm normally happy to see at least 4.75. Is this ok for this board or should I try to up it a bit? I've seen a few systems that liked it closer to 5.1

4) I'd also check the status of your ribbon cables between the CPU and the widget/ROM boards, as they can cause problems as well....

I'll give them a close check out.

Thanks for the tips

Plaz
 
you should buy from member jrok his 19 in 1 and put that in the defender cab. it has 19 games like defender, stargate, joust, sinistar, bubbles, uhhh i cant remeber all them right now but it rocks! you will have to add a joystick to the CP and a button for inviso.

That sound cool (and expensive?) Do you have a link, or I'll search around a bit and see if I can find it.

Plaz
 
I've tracked and repaired a couple more issues causing bad logic on the data bus and the rug test is looking much better (but not perfect), but now here's the interesting part....

At boot up I get the ram error code 1-1-1. But I know the ram, and socket there are good and signals on all pins look ok. (Any one have signal diagrams from a good system?) If I pull a ram chip from any where in bank 1 or 3, the error code corresponds to the correct ram position I just pulled. ie 1-1-6, 1-1-8, 1-3-5. However if I pull a ram chip from any where in bank 2, the returned error is always 1-1-4. Any chip pulled in bank 2 reports an error in bank 1 socket 4 ??? Surely some thing odd going on in address decoding.

Plaz
 
You may have the decoder locations backwards, that will also cause this issue. Verify that you have the decoders in their correct sockets.
 
I've got a couple of photos to share, one each of a typicall ram data out and data in on my board. You'll have to excuse my old/slow scope. It tends to round off and attenuate faster signals and some times it's hard to sync in a good spot causing over lapping pulses. Even so, do these look any thing like a working board. The input signal looks more like an analog signal than digital to me. You can see these patterns pulse and change as the initial rug test runs.

Typical DRAM input signal at pin 2

RamDataIn.jpg


Typical DRAM output signal at pin 14

RamDataOut.jpg


Plaz
 
You may have the decoder locations backwards, that will also cause this issue. Verify that you have the decoders in their correct sockets.

The original labels are in bad shape and have S-T-A-R written accross them in fat marker. No way to read what original codes might have been printed there. It's my guess these might have been reburned from defender to stargate decoders. Do the bins for these exist that I might do a bit comparison to confirm which is which an that they are programmed correctly?

Just on a chance I swapped them. The board gives a constant ram error of 1-3-5 and no longer properly recognises when I pull the chips from banks 1 and 3 as before. I'd guess they were in the right positions, but I'm still not convienced one might not have a problem.

Plaz
 
Just on a chance I swapped them. The board gives a constant ram error of 1-3-5 and no longer properly recognises when I pull the chips from banks 1 and 3 as before. I'd guess they were in the right positions, but I'm still not convienced one might not have a problem.

Plaz

The constant 1-3-5 indicates that they were in correct position originally. You may still have one of the two that is bad.
 
Thank you for taking the time to restore this Defender, instead of trashing or MAMEing it..

You're welcome. :) I normally prefer restoring old stuff when possible. If this cabinet had been gutted, it probably would have already been sporting a mame configuration weeks ago. Once I saw it pretty much had all the boards and bits, I just couldn't think about messing it up with out cringing. Once it's complete I may add some mods, but it will look and play original. It is taking much more time than I hoped though. I would like to get it finished up soon. It's slowing me up on my next restore project..... 1969 AMC V8 Javelin. :)


IMG_2010-1-1.jpg


This is what they should look like...
http://en.wikipedia.org/wiki/AMC_Javelin

Plaz
 
The constant 1-3-5 indicates that they were in correct position originally. You may still have one of the two that is bad.

Thanks for confirming. Now I'm off to find some binaries.

Plaz
 

Hard to tell from that pic, but it almost looks like the AMX 390. (X Block)

Had a 71' SST, and a 72' SST (3rd owner 92K original) Loved those 2 cars, both were faster than shit, and I still got 21mpg on the highway out of them. Both with 304's in them.
 
Hard to tell from that pic, but it almost looks like the AMX 390. (X Block)

That's great, another Jav/AMX fan. In 68-70 the AMX was a separate two seater version from the Javelin about 12 inches shorter. At a glance they look nearly identical though. In '71 they melded the Javelin/AMX into one model, also known as the "humpsters". They were longer than the 68-70 with the "humps" in the front fenders, but sported much of the same hardware. In the 68-70 Jav/AMX you could get a V8 at 290,343 or 390. From 70-74 they came as 304, 360 or 401. As you would know, lot of folks are suprised at the power these will make. Plenty of competition for the better known fords, chevys and chryslers. I've got a rebuilt 304 ready to go when the body work is done. I also just picked up a 360 that I may rebuild instead

Just after I got out of high school, I got a 12 year old 68 Javelin with a 290. It ran like a monster and still got 21-22 mpg. Great stuff for that time while I trying to go to school. 28 years later when it came time to decide on a car to restore, the memory of my old Jav stood out. Besides, every one already has a Mustang or Charger.

What's all this got to do with Defender/Stargate? I got back in to electronic repair to help pay for the car project. :)

Plaz
 
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What's all this got to do with Defender/Stargate? I got back in to electronic repair to help pay for the car project. :)

Plaz

Absolutely nothing.:D The 360 was the dog, out of the engines that were used in those cars. There were 2 different versions of the 390. The standard put out 305hp and the X-Block put out 335hp stock. The 401 Police interceptor was wicked too.
 
The constant 1-3-5 indicates that they were in correct position originally. You may still have one of the two that is bad.

One more test...
With the decoder at 3G removed, the error code changes to 1-3-1 and remains that way no matter what other ram chips I pull.

If pull the decoder from 3C, that familiar 1-1-4 error code returns... but the error code will change to the correct corresponding error code if I pull a ram chip from banks 1 or 3.

It would seen that decoder 3C, or some thing related to it, is not working properly.

Plaz
 
Absolutely nothing.:D The 360 was the dog, out of the engines that were used in those cars. There were 2 different versions of the 390. The standard put out 305hp and the X-Block put out 335hp stock. The 401 Police interceptor was wicked too.


Well the 360 was certainly the little brother compared to the 390 and 401, but built right it will do 300+hp. And these days I'm as interested in the gas milage. Some of the racers have gotten 400+ out of a 360. But then you can get 500+ out of a 390/401. :)

Plaz
 
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