Sinistar Updated PS Question

jgeiger

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Hi,

I updated the power supply in my Sinistar to a switching ps from Bob Roberts. Works great with one exception. The game decided to forget the settings and switched back to the factory defaults. This includes free play. With the new power supply I dont have power to the coin door to either coin it up or adjust the settings again. Whats the best way to either coin it up without the coin door or get the coin door wired back up?

Thanks.
 
The coin door connector contains the ground line. You need to run that ground line to the switching power supply ground.

I am really suprised this wasn't detailed in the instructions from Bob. I thought his kit made provisions for this.

ken

Edit: Get ready to keep losing your high scores and settings. Williams classic games don't play well with switching power supplies. The explaination has been posted many times.
 
Awesome. I may have overlooked it in his instructions. Thanks for the help.

Also, I am hoping to eventually rebuild the original power supplies (I have 4 Williams games) and get them back in there. Just wanted to get them up and playing.
 
That worked. I found the web page from Bob explaining what the deal was. Thanks for pointing me in the right direction.
 
No problem. It is a very common mistake. People that sell these replacement power supplies really need to make that very prominent in their instructions.

ken
 
I looked at one of these original Williams Sinistar power supplies today, the +5 was way low 4.78 at 74lsxx chips. Disconnecting all other boards did NOT help. Looking at input, it is about 2 volts low, 9.98-10.1, should be unregulated +12. Output from regulators are right about 4.78. Noticed power cord wired bad and nicked so will fix that first and re test. My question; is the +5 adjusted with 1% resistors.
 
No problem. It is a very common mistake. People that sell these replacement power supplies really need to make that very prominent in their instructions.

ken

People should quit using switchers in Williams games and that would solve the problem.

I looked at one of these original Williams Sinistar power supplies today, the +5 was way low 4.78 at 74lsxx chips. Disconnecting all other boards did NOT help. Looking at input, it is about 2 volts low, 9.98-10.1, should be unregulated +12. Output from regulators are right about 4.78. Noticed power cord wired bad and nicked so will fix that first and re test. My question; is the +5 adjusted with 1% resistors.

No.
You need to rebuild the power supply if the voltage is that low.
 
I looked at one of these original Williams Sinistar power supplies today, the +5 was way low 4.78 at 74lsxx chips. Disconnecting all other boards did NOT help. Looking at input, it is about 2 volts low, 9.98-10.1, should be unregulated +12. Output from regulators are right about 4.78. Noticed power cord wired bad and nicked so will fix that first and re test. My question; is the +5 adjusted with 1% resistors.

No.
You need to rebuild the power supply if the voltage is that low.

Agreed. Playing with the reference resisters could work, but it is a recipe for disaster. You are much better served by rebuilding the PS board.

If the unregulated power is running low, most likely the Bridges are getting ready to go and/or the fuse clips are corroded not allowing sufficient amperage through.

People should quit using switchers in Williams games and that would solve the problem.

That would solve the problem, but we both know that they won't.

ken
 
Good info guys and thanks....I will re test after replacing power cord and if power is still low will re build supply or send out for re build.
 
At least he said, "updating" and not upgrading, because we all know that a switcher in a Williams game is NOT an upgrade.:eek:

Thanks for saying that. I get so tired of hearing people put in a switcher in place of the original linear power supply. All mine are all original. No memory problems at all. When they have voltage problems, I rebuild them and they are good to go.
 
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