Front line voltage

Talsivar

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Donor 2012, 2024
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The game wasn't booting Has a switchable power supply with the Taito adapter. If I set the power supply at 5 v when it gets to the power at the board it is only 4 v. If I crank it all the way up as far as it goes 6v at the switcher I get to 4.89 at the board and it will boot. The yellow wires though crank up to over 16v when I do that. Am I wrong to think that is to high? And even with that I'm still under 5v at the board.
 

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The game wasn't booting Has a switchable power supply with the Taito adapter. If I set the power supply at 5 v when it gets to the power at the board it is only 4 v. If I crank it all the way up as far as it goes 6v at the switcher I get to 4.89 at the board and it will boot. The yellow wires though crank up to over 16v when I do that. Am I wrong to think that is to high? And even with that I'm still under 5v at the board.
yes, it's not the power supply, it's the wiring and connections from it, or more specifically the return path isn't good. it could be not enough grounds, bad plug, bad header pins. look at the underside of the board where the power header pins are and see if there's additional unused ground pads. add 18 gauge wire accordingly.

there's a lot of empty holes in that plug so you might be able to 2 more grounds and another +5V wire.
 
Checking grounds I found this, they had them just tucked under these washers.
 

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yes, it's not the power supply, it's the wiring and connections from it, or more specifically the return path isn't good.

Might be a dumb question, but what points specifically to the ground path? Something about 16V seen on the 12V feed?

Another rookie question, do the game boards typically get grounded to the braided strap? Or does the ground go all the way back to the supply?
 
Checking grounds I found this, they had them just tucked under these washers.


Those are field grounds. They are not part of the power circuit, and are not the problem.

You could rip out field grounds, and the game will still play fine. They are there to protect YOU against being electrocuted. They are not used for board power.

Clean your edge connector fingers, and DeOxit them.
 
Those are field grounds. They are not part of the power circuit, and are not the problem.

You could rip out field grounds, and the game will still play fine. They are there to protect YOU against being electrocuted. They are not used for board power.

Clean your edge connector fingers, and DeOxit them.
it's header pins. Tah-ee-to, not Irata. lol

I would replace the power plug and pins mandatory.

@Talsivar post a picture of the underside of the board where the power header is please and thank you
 
Was that a dumber question than i thought? There is 1v drop but I didnt see anything there that pointed to the drop being on the feed or ground.

Those are field grounds. They are not part of the power circuit, and are not the problem.
Thats what I thought, but given my recent track record thought it was safer to ask than give bad advice.
 
Have you tried cleaning the pins on the filter board that is on the bottom of the back door, those could be causing issues with the voltage maybe causing resistance as there dirty or corroded
 
I'm losing the power at this connector before it even plugs into the board. I followed it back to the connector board and where it plugs in I get the same reading as on the power supply. So somehow I'm losing voltage from one end to the other.
 

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I'm losing the power at this connector before it even plugs into the board. I followed it back to the connector board and where it plugs in I get the same reading as on the power supply. So somehow I'm losing voltage from one end to the other.
I'm not sure how thats possible unless it is connected to something else in the harness that is drawing enough current to pull it down 1V.
 
I'm not sure how thats possible unless it is connected to something else in the harness that is drawing enough current to pull it down 1V.
All the wires are zip tied together I haven't seperated them yet to see where they all go. I did clean all the connections with detoxit and am now getting better readings. I was able to lower the power supply some and have 4.69 and just under 13v now at the plug. It will boot and play now but still not ideal. I don't know maybe the voltage is fluctuating and it's giving me false readings.
 
Have you measured voltage on the pins on the adapter attached to the power supply, I know you showed measurements at the terminal screws, could that adapter be bad? Maybe solder joints to the pins
 
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