PS Voltages Tanking When 1 Slot Neo Board Installed

nerdygrrl

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PS Voltages Tanking When 1 Slot Neo Board Installed

I have been trying to put together a Neo Geo cab with a one slot board for a friend. The one slot PCB is tested and working in my two slot cab.

I installed a brand new Suzo Happ 130W Power Pro Power Supply Part # 80-0210-00
https://na.suzohapp.com/products/power_supplies/80-0210-00

When I plugged it in and tested voltages I was within range on the PS and at the end of harness. When I plug the PCB in the PS stars to squeal and the voltages plummet.

The neg 5 stays within range, but the +5 drops to around 3 and the 12V is basically MIA.

I know my 2/4 slot boards need more power and the cabs usually come with a 150W PS, but I thought the single slot boards were ok with a normal 115W switcher.

I should add I am using a used Neo 4 slot harness in here, but assumed it was ok, given the voltages at the edge connector are cool when tested w/o board.

Any ideas on what would cause the PS to tank like that? Should I toss a 115W in and see how it goes?
 
I should add I am using a used Neo 4 slot harness in here, but assumed it was ok, given the voltages at the edge connector are cool when tested w/o board.

you can damage the switcher if there isn't a +5v dc "load" on there
all the Bob Roberts switchers came with that warning on a label there

I would verify each and every wire in that harness to and from where they go whilst looking at the pinout of each pin inside the connector and it all of it
for fun you could do a continuity on each wire too to verify you don't have any broken copper inside the insulation there where you cant see it

power supply may be damaged. I don't know. I have here an old board that I use that I don't care if it gets fried so as to check the voltages on the power supply
 
Double and triple check your wiring, and check the board again on your other cabinet.

I've had switchers drop the voltage like that when there's a dead short across 5v and ground.
 
I had a shorted 5V and I ran a new wire. It's booting ad playing blind now.

I have a Suzo Happ Vision Pro LCD in the cab, but it's not getting video signal. I tried it in my 2 Slot and no signal there either. Monitor works and tests fine in my Gyruss and Ms Pac though.
 
Some monitors have trouble with the neo geo's sync line, it seems. Try a 470 ohm resistor between csync and video ground. I've heard that works for wei ya monitors, at least.
I think the vision pros won't display anything if it doesn't sync up right.
 
Some monitors have trouble with the neo geo's sync line, it seems. Try a 470 ohm resistor between csync and video ground. I've heard that works for wei ya monitors, at least.
I think the vision pros won't display anything if it doesn't sync up right.

Many thanks! It's been driving me nuts!
 
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