Galaga edge connector 5v disappearing when connected

KidVidiot

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Jamma bootleg Galaga pcb in Galaga cabinet all of a sudden stopped booting at all. Traced 5v which was now missing at the board. With the edge connector unplugged from the pcb I get the proper 5v but immediately upon connecting it the 5v disappears. The edge connector plugged into the jamma adapter with no pcb gives me 5v reading but not when adapter is connected to pcb. Same thing happens without the jamma adapter when I try plugging the edge connector directly into the original pcb. The cabinet has a switching power supply + adapter as well.
 
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Sounds like either the power supply is dying or the board has a fault that's causing the power supply to shut down. Since it's a JAMMA bootleg, do you have another JAMMA board you could test with? Or another power supply?

DogP
 
Sounds like either the power supply is dying or the board has a fault that's causing the power supply to shut down. Since it's a JAMMA bootleg, do you have another JAMMA board you could test with? Or another power supply?

DogP
What's weird is that it is happening when I plug the original galaga edge connector into the original galaga pcb as well. Forgot to mention I also have a switching power supply + adapter in the cabinet. Feels like I should swap the ps and try a different jamma board just to see what happens.
 
What's weird is that it is happening when I plug the original galaga edge connector into the original galaga pcb as well. Forgot to mention I also have a switching power supply + adapter in the cabinet. Feels like I should swap the ps and try a different jamma board just to see what happens.
Sounds like you have a bad PS. It can't hold the 5V when you apply a load. You could verify this by using a resistor as a load (but make sure the power rating is good first. Ohm's law is your friend)
 
What's weird is that it is happening when I plug the original galaga edge connector into the original galaga pcb as well. Forgot to mention I also have a switching power supply + adapter in the cabinet. Feels like I should swap the ps and try a different jamma board just to see what happens.
You just eliminated everything but the PS.
 
Sounds like bad caps 0n the PS. I had the same thing happen with a PS in a Tivo several years back. Got 5v with no load but got 2v when connected. Had two bad caps. changed them out and was back in business.
 
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