Noob question-What do I need and how to change voltage?

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OldFoo

Noob question-What do I need and how to change voltage?

Post by OldFoo »

Hey there.



I'm mentioned in other threads this same thing, but it's true. I'm extremely new to arcade cabinets, and even newer to the Naomi. I have a New Astro City cabinet with a few PCBs-Neo Geo 1 slot with 150 in 1 multicart, MK 2 v. 3.1, and KI.



I will be receiving by Naomi starter kit either today or tomorrow. It's a Naomi 1 MB and Capcom I/O, along with Powerstone. Now for my questions.



I continue to read about the Naomi needing +5.1v, and if you encounter problems, make sure you're running +5.1v. I've checked the front of my power supply and it says +5, +12, and -5. My questions are: What do I need to check this, how do I check it, and finally how to adjust the voltage to 5.1? I'm sorry I put this in the "technical" section as I'm sure it's not technical to many but I'm really a blank slate when it comes to knowledge on this subject and I want to be able to enjoy the Naomi without too many starter hiccups. From what I've read here's what I think I know.....



I believe I'd need a voltage meter. I've read about the "chopsticks", multimeter (supposed to be about 10 bucks). Also I've noticed on my power supply, on the top it says "v. adj" and there's a small hole there. Is that where I'd adjust the voltage to make it 5.1v? Also what would I use (jokes aside here folks..lol) to adjust it? Once adjusted, where am I supposed to take the reading-from the jamma harness, somewhere else, and if so, how to take the reading? Any and all direct, easy to follow directions would be helpful. I'm sorry if this is a repeat thread as I'm sure these questions are asked all the time.[/img]
OldFoo

Post by OldFoo »

Not silly at all to ask these questions. You know what? I will take some pictures of my New Astro City detailing what you need to do, and post them later tonight, ok?
OldFoo

Post by OldFoo »

Sounds awesome to me. The help is greatly appreciated.
OldFoo

Post by OldFoo »

Well my Naomi stuff arrived today and no hiccups at all. It's running Powerstone just fine in 15k mode (I don't have a 31k monitor), and looks pretty darn good...



I'm still curious how to go about adjusting the voltage as I believe it's a good thing to know, but yeah, guess I was surprised it worked right away. And I guess I never know when problems might be lurking around the corner...lol.



Is the whole 5.1v thing a definite rule for the Naomi to function properly or is it not that simple?
OldFoo

Post by OldFoo »

Also, as I just got the Naomi I do have a completely non-technical question...



Is it supposed to be so loud when it runs? I mean it's not that loud, but you do hear it (the fan I'm assuming) running. I guess I've just grown accustomed to PCBs without fans, so everything is completely silent, and atm, I'm running it outside of the cabinet.
OldFoo

Post by OldFoo »

ok, so what you will need is a simple multimeter that has the ability to measure DC voltages. Mine is not the cheapest, but to give an idea:

Image



Now, at the Naomi, stick the black and red probes in the power connector, as shown below (black probe at white wire, red probe at yellow wire). Put them in far enough so they touch the metal parts where the wires meet the connector pins:

Image



Now read the voltage on the multimeter. It should read about 5.1 volts:

Image



Also probe the other connector on the Naomi, just for double checking:

Image



Tuning the 5V line (depending on what PSU you have) can be done using the v.adj potmeters on the NAC PSU (on the top):

Image



or on the Naomi PSU:

Image



As you can see, you can use a small Philips screwdriver to adjust the voltage. A method to do that is to keep the multimeter connected, slowly turn the potmeter and watch the multimeter to monitor the change.
Last edited by OldFoo on Sat Aug 14, 2010 12:45 pm, edited 1 time in total.
OldFoo

Post by OldFoo »

Perfect. Thanks for the helpful pictures. That is exactly what I needed. I think I'll pick up a meter today as I'm curious what my machine is running considering it seems to run the Naomi with no problem.
OldFoo

Post by OldFoo »

DrGraffin wrote:Perfect. Thanks for the helpful pictures. That is exactly what I needed. I think I'll pick up a meter today as I'm curious what my machine is running considering it seems to run the Naomi with no problem.


You're welcome.



Yeah, no harm in checking. The cheapest multimeter I have was 10 dollars, and does a fine job at checking simple things like this.



Oh, and the Naomi is noisy. The case fan in the Naomi can easily be replaced by a fan that produces less noise. It is a simple 60mm two-wire 12V fan. I put a Papst fan in mine (requires cutting wires, though):



http://www.ebmpapst.com/de/products/com ... ?pID=53767



This will reduce the noise level produced by the Naomi, although the internal fans on the motherboard can be quite noisy as well. Replacing those is somewhat tricky, as there is no easy replacement.
OldFoo

Post by OldFoo »

Those pictures are so direct and easy to understand...I think it'd make a great addition to the FAQ about getting started with Naomi, what you need, and how to troubleshoot easy problems...But that's just me...
OldFoo

Post by OldFoo »

Topic moved from Technical to FAQ section. :smt023
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