SOLVED: Gorf's 90411 linear PS - no sound BUT produces all the proper voltages! It's NOT the amp PCB!

texasmame

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First off, boardset, harness, and amp board known good.

When I use a switcher with the Arcade Shop adapter for Gorf, I get all the sounds just fine.

When I plug in the linear 90411-B000, it produces all the voltages and the game plays but there is no sound at all. Double-checked all the grounds and they all show continuity with each other and the grounding prong on the plug. All PS connectors cleaned, desoldered and resoldered.

Since this is producing all the proper voltages, and you can adjust each via their pots, AND the grounding also appears correct, I'm stumped.

Input appreciated.
 
Did you actually verify that the amp is getting the voltage? You can use test points on the supply and measure fine, but if it isn't making it to the amp due to a harness problem then it won't work.
 
When I use a switcher with the Arcade Shop adapter for Gorf, I get all the sounds just fine.
 
That doesn't change what I said. Are you measuring right at the connctors or are you measuring at the caps. You can have a break somewhere on the supply or something.
 
There isn't much that makes the power for it.
Screenshot_20250904-124328.jpg

Gorf uses an unregulated 12V, the actual supply voltages mean nothing from the amp perspective. The reason it might be working on the arcade shop supply is because the arcade shop supply uses the regulated 12V supply. This doesn't. If you haven't done so, check the fuse and fuse holder. Make sure you get your 13 or 14V across pins 1 and 11. If you get it fine then I don't know.
 
Just one additional thought related to the post above: cold solder joints on the power supply PCB itself (diodes, filter cap, etc.)

They are notorious for passing voltage at no-load or light load, but the voltage drops significantly under load.
 
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