Stargate Power Supply

FrizzleFried

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It appears the Williams PS in the Stargate I have is not outputting +5v. Are the Williams PS's known for being crap? Should I throw a switcher in there to provide the +5? I see the PS outputs -12v too, I don't think a switcher does -12v, right?

Would it just be wiser to ask in the WTB for a Williams PS?
 
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I've heard that they were crap from friends who have had them. I'm picking up my first Williams game next week, so I'm no expert. Well it appears I heard wrong. Quietly backing up and leaving the room.
 
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They are one of the most reliable power supplies available when they are taken care of. The ones that are failing are over 25 years old and have had very little done to them.

Switchers do NOT put out -12vdc, and using the -5vdc in it's place sometimes causes the sound card to fail.
 
They are one of the most reliable power supplies available when they are taken care of. The ones that are failing are over 25 years old and have had very little done to them.

Switchers do NOT put out -12vdc, and using the -5vdc in it's place sometimes causes the sound card to fail.

So would you recommend a WTB: WORKING WILLIAMS PS?

...and are all Williams PS of the same era the same?

Quarterarcade has this one for $16.00...EDIT: That was untested. I wonder if Bob sells Williams PS rebuild kits.

 
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Just tell me what you need. I have a tested working one (recapped, with adjustable +5vdc mod) that I will sell you for $20 shipped exchange. (meaning I want your dead one)

Stargate, Defender, Make Trax are all the same.
Joust, Moon Patrol, Robotron, Bubbles are all the same.
Basically only two different styles were used.
 
Bob Roberts sells several different Williams power supply rebuild kits:

Connectors only kits.

Capacitors/bridge rectifier/transistors/IC's only kit.

Complete kits with all male & female connectors, capacitors, bridge rectifier, transistors, and IC's.
 
It appears the Williams PS in the Stargate I have is not outputting +5v. Are the Williams PS's known for being crap? Should I throw a switcher in there to provide the +5? I see the PS outputs -12v too, I don't think a switcher does -12v, right?

Would it just be wiser to ask in the WTB for a Williams PS?

As Dok said Williams Power supplies are incredibly reliable, if they are properly maintained (and generally even if they are not). Many are stil working reliably after 30 years. The same can't be said of switchers, many of which won't see their 5th birthday.

There are two different power supplies that were used for Stargates. Early ones used the Defender Power supply (both transistors with heat sinks on the ps board). Later ones used the power supply that was used in Robotron/Joust and later (the transistors are on a separate heat sink).

I have rebuilt boards in both versions available for $35 shipped to the lower 48, slightly higher elsewhere. The Robo/Joust version is just the ps board, it does not include the heat sink with the transistors.

To answer the question one more time, you do not want to put a switcher in a Williams box. You can get switchers that supply all 4 voltages (+5, -5, +12 & -12), but the Williams boards take advantage of the design of the PS boards to kick the CMOS protection circuit in while the +5 V is dying. This prevents the CPU from trashing the CMOS. Switchers will not hold the +5 volt and consequently the CPU can trash the CMOS randomly.

ken
 
To answer the question one more time, you do not want to put a switcher in a Williams box. You can get switchers that supply all 4 voltages (+5, -5, +12 & -12), but the Williams boards take advantage of the design of the PS boards to kick the CMOS protection circuit in while the +5 V is dying. This prevents the CPU from trashing the CMOS. Switchers will not hold the +5 volt and consequently the CPU can trash the CMOS randomly.

ken

I had this problem a lot in my Williams multi when it had a switcher in it, haven't had the problem at all since I went back to original.
 
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