Help; Switching Power Supply reading higher than it should

McCHitman

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Help; Switching Power Supply reading higher than it should

I'm currently trying to get a Neo Geo MVS cabinet working. It was completely gutted and I'm following a diagram on the Hardmvs site for the wiring.

http://www.hardmvs.com/html/powerBoard2.htm

I have everything hooked up and I'm checking the connections with at Multimeter and none of the numbers on the Power Supply read correctly. They are close but not exact, the +5 is at 7, the +12 is at 19 and the -5 just shows -0. I have it adjusted as low as it will go and was wondering if I should get a new Switching power supply or will this be ok without any problems to my monitor or board.

Thanks
 
Do you have loads connected? With switching power supplies, no loads = no likey due to they need the load in order to stabilize properly. Check the specs of the power supply and ensure you have at least the minimum required load.
 
Do you have loads connected? With switching power supplies, no loads = no likey due to they need the load in order to stabilize properly. Check the specs of the power supply and ensure you have at least the minimum required load.

Loads...Nothing is hooked up to it. My setup is identical to the link I posted in the original post. I'm at the final steps, testing it, but that page doesn't say anything about having any thing else connected to it.

The Isolation Transformer, AC Distributor, and line filter all check out how they should. It's just the Switching Power Supply that is giving me readings that aren't where they need to be. I can make them higher by adjusting the dial, just not lower than what it's at.


The Power Supply is some Chinese brand, Xin Xing ,that didn't come with a manual or anything so I have no info on it at all; Got it from Amazon.
 
you can fry some of the switchers if they dont have a load on there when you turn it on...

read ages ago you can hook up an 80 watt light bulb to the +5v so you can test the switcher...
 
you can fry some of the switchers if they dont have a load on there when you turn it on...

read ages ago you can hook up an 80 watt light bulb to the +5v so you can test the switcher...

You need to have a load on the switchers to have them work proper. Also when I have erronious readings on a meter, I change/check the battery as that is used for the reference. If the battery is weak or close to dead you will have readings all over the scale.

I personally like the light bulbs for testing supplies, you can watch them over a period of time and see if it fluctuates some or a lot just by looking at it. Car light bulbs work just fine, 12v ones on the 12 volt line and 5-6.3 on the +5 line.
 
You need to have a load on the switchers to have them work proper. Also when I have erronious readings on a meter, I change/check the battery as that is used for the reference. If the battery is weak or close to dead you will have readings all over the scale.

I personally like the light bulbs for testing supplies, you can watch them over a period of time and see if it fluctuates some or a lot just by looking at it. Car light bulbs work just fine, 12v ones on the 12 volt line and 5-6.3 on the +5 line.

Ok, how do I go about hooking a light bulb up to the power supply? At this point, I don't even know how to connect my monitor to this thing. First time doing this.
 
I do not know about the light bulb, one of these other guys who knows far more than I do will have to help you there. However, I can make a recommendation as someone who just recently myself (within a year) learned how to work on arcade machines. You should look into getting a test board. Meaning, a jamma board, that fully works, which you do not pay very much for. There are many things a test board can help you with by hooking it up to your cabinet (Neo Geos are jamma) and turning it on to test things like power supplies (which you could use right now), sound, monitors, etc., without jeopardizing your good pcb. As a rookie, I cannot express enough how much a test board will help you. I use a Capcom Bowling I paid $15 for. Some guys use Street Fighter II boards, which is sad to me, but to each their own. Good luck, and continue to use this forum, these guys have an invaluable breadth of knowledge.
 
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Ok, how do I go about hooking a light bulb up to the power supply? At this point, I don't even know how to connect my monitor to this thing. First time doing this.

If you are having trouble with a Power Supply blowing fuses and are not sure if you got the problem fixed, here is a tip. Get a lamp socket with 2 extending leads and a light bulb. Solder alligator clips on the leads. Put the clips in place of the fuse. Power up the PS and turn on the bulb. If the bulb goes extremely bright on power up, the short is still present. If it goes dim more than likely the Power Supply will start working properly. It may take a few seconds or flicker if the power supply is a Switching Power Supply. This will save you time and money!

This was copied from this site:

http://www.anatekcorp.com/ttg/tiptrick.htm#Testing Power Supplies

The idea is the same; get a light blub and solder wires to it or get a socket for it with leads coming from it. Just place one on the + of the output of supply and one on the - of same supply. Polarity of the bulb doesn't matter, also ac or dc doesn't matter with incandescent bulbs. You can use a car test light but be sure it is hooked up BEFORE you power up.

A 12 car break light bulb will work fine, maybe get one from a junk yard with the socket and wires.
 
The idea is the same; get a light blub and solder wires to it or get a socket for it with leads coming from it. Just place one on the + of the output of supply and one on the - of same supply. Polarity of the bulb doesn't matter, also ac or dc doesn't matter with incandescent bulbs. You can use a car test light but be sure it is hooked up BEFORE you power up.

A 12 car break light bulb will work fine, maybe get one from a junk yard with the socket and wires.

Oh ok. Thanks,
 
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