12v not working on 2 PSUs

[OldFoo]

Hi everyone, I picked up a naomi universal a bit ago , but had to disassemble it before transport due to space. Because of this, the bottom half was exposed and the nearest I can think is that I knocked a wire. When I tested it with the PSU that was already in it (through transport) it gave 3.3, 2, 2. So I got a new power supply, slightly better with 3.3, 4.9, 0. So I have no idea why I'm not getting 12 volts. If anyone else has a naomi uni and wouldn't mind taking a pic of the power wiring, it'd be very helpful, thanks.



http://imageshack.us/f/846/20111118183846886.jpg

http://imageshack.us/f/21/20111118183822336.jpg/

http://imageshack.us/f/23/20111118183814817.jpg/

[OldFoo]

Hi everyone, I picked up a naomi universal a bit ago , but had to disassemble it before transport due to space. Because of this, the bottom half was exposed and the nearest I can think is that I knocked a wire. When I tested it with the PSU that was already in it (through transport) it gave 3.3, 2, 2. So I got a new power supply, slightly better with 3.3, 4.9, 0. So I have no idea why I'm not getting 12 volts. If anyone else has a naomi uni and wouldn't mind taking a pic of the power wiring, it'd be very helpful, thanks.



http://imageshack.us/f/846/20111118183846886.jpg

http://imageshack.us/f/21/20111118183822336.jpg/

http://imageshack.us/f/23/20111118183814817.jpg/

Try test the continuity using a multi-meter on the 12v wires to make sure there's no breaks.

[OldFoo]

Try test the continuity using a multi-meter on the 12v wires to make sure there's no breaks.

+1 .



If you're psu dont work after the continuity test , I've a naomi's psu for sell at 30e.

[OldFoo]

Here's a tip that I would recommend trying. Find a 12v wire in the system (not the PSU). Put your meter into 'continuity mode' or whatever your meter has to test for wire breaks. Put one lead to the 12v wire and any available ground. If you get continuity (usually a tone), then you have a short somewhere. If so, you need to fix this before you fry another PSU.

:smt073

[OldFoo]

Sorry for the delayed response (love final exams), and thanks for the help so far.

Try test the continuity using a multi-meter on the 12v wires to make sure there's no breaks.

Well, I don't have a continuity test, but I have a resistance check. Wires from PSU to naomi don't have any.

Here's a tip that I would recommend trying. Find a 12v wire in the system (not the PSU). Put your meter into 'continuity mode' or whatever your meter has to test for wire breaks. Put one lead to the 12v wire and any available ground. If you get continuity (usually a tone), then you have a short somewhere. If so, you need to fix this before you fry another PSU.

:smt073

I ran the same test on each of the wires going to the naomi using the ground below them. I got .27 for the 12v, .04 for the 5.5, and .11 for the 3.3. So, I guess there's the problem then. Thanks.

[OldFoo]

Sorry for the delayed response (love final exams), and thanks for the help so far.

Try test the continuity using a multi-meter on the 12v wires to make sure there's no breaks.

Well, I don't have a continuity test, but I have a resistance check. Wires from PSU to naomi don't have any.

Here's a tip that I would recommend trying. Find a 12v wire in the system (not the PSU). Put your meter into 'continuity mode' or whatever your meter has to test for wire breaks. Put one lead to the 12v wire and any available ground. If you get continuity (usually a tone), then you have a short somewhere. If so, you need to fix this before you fry another PSU.

:smt073

I ran the same test on each of the wires going to the naomi using the ground below them. I got .27 for the 12v, .04 for the 5.5, and .11 for the 3.3. So, I guess there's the problem then. Thanks.

0. for the voltages? Definatly. And if you don't have a continuity tester, it's easy to make one. Just get a battery and an LED with a resistor on one leg. Attach on leg to the battery (shorter leg to negetive or longer to positive), attach the other to one wire and the other battery terminal to another wire. It'll light if there's a short.

[OldFoo]

Sorry for the delayed response (love final exams), and thanks for the help so far.

Try test the continuity using a multi-meter on the 12v wires to make sure there's no breaks.

Well, I don't have a continuity test, but I have a resistance check. Wires from PSU to naomi don't have any.

Here's a tip that I would recommend trying. Find a 12v wire in the system (not the PSU). Put your meter into 'continuity mode' or whatever your meter has to test for wire breaks. Put one lead to the 12v wire and any available ground. If you get continuity (usually a tone), then you have a short somewhere. If so, you need to fix this before you fry another PSU.

:smt073

I ran the same test on each of the wires going to the naomi using the ground below them. I got .27 for the 12v, .04 for the 5.5, and .11 for the 3.3. So, I guess there's the problem then. Thanks.

0. for the voltages? Definatly. And if you don't have a continuity tester, it's easy to make one. Just get a battery and an LED with a resistor on one leg. Attach on leg to the battery (shorter leg to negetive or longer to positive), attach the other to one wire and the other battery terminal to another wire. It'll light if there's a short.

Ah, sorry, I meant 0 resistance (I don't know what it's measured in, working with arcades is my first bit of actual electronic background, I'm more used to computers). I'll see if I can try to make that continuity tester, I think part of the problem is there are two grounds that I think I didn't put back together right. Thanks again for the help

[OldFoo]

Ok, I ended up giving up on it for a bit to work on slightly easier problems (IE: adding buttons, swapin games), but now that I think I have most of my other problems finally worked out, I think I'm ready to try this again.



So, apparently leaving it set for a couple of months was a bad idea, because now the semi-dead power supply isn't getting any power at all. I did end up finally picking up a decent multimeter to test continuity and correct voltages, none of the lines to the mobo were grounding out and connected fine, but I couldn't get continuity for the main power. So I don't know if I was testing the wrong wires, but when I connected the power supply and a power cord, nothing happened.



So, I don't know, should I just undo the the wire-ties and test everything? Is a part broken? Did I just mess up the test?







edit:forgot image

[OldFoo]

When checking the voltages going INTO the PSU, what do you measure? Nothing? If so, check for a blown fuse between the mains and the PSU (there is probably a mains filter in between as well).

[OldFoo]

Finally got back to working on it. Ended up tearing apart the wires that were bound together so I could actually trace their path. tested continuity on everything up to the power supply. Was fine. Tested voltage into power supply, 117V. Tried to test amperage in, but couldn't figure out how (was comming up 0). Everything seemed good to go so I swapped out for the power supply I picked up a while ago and... 3.3 fine. 5v fine. Still no 12.



I don't know what else to do with it. I think I might just use a computer power supply. So I got a few more questions.

1.Any idea why the 12v keeps dying?

2.If I use an ATX power supply with 12/5/3.3v out, do amps matter?

3.If I use an ATX power supply, can I use the white/black wires + ground instead of main? the monitor is powering on fine, its just the naoimi+sound+io that isn't liking not having 12v



Edit: So it wasn't the wires into the power supply, it was one of the wires out. I had the IO's 12v power in the wrong way. Took 8 months and 2 power supplies to figure that out. Just goes to show that testing ALL the wires before making a decision is probably a good idea.