System 256 and Boardmaster Supergun

[Eddierang]

Looks like it’s something more serious than replacing the fuse. I replaced the 1A fuse on the 12V line, fan on the system 256 started working, and then it crapped out again, so I blew the fuse unfortunately. Something is shorting the 12V and I’m not sure what it is.

[grantspain]

i would imagine 1a 12v supply is too low, 4a is the normal on a jamma supply for 12v and 16a for 5v line
namco system boards are quite power hungry

[Eddierang]

Ok, well if that’s the case I saw on YouTube, Nozomi7585’s YouTube channel that the system 256 worked on his boardmaster when putting in Capcom Fighting Jam. Did he mod his boardmaster with higher current fuses?

[grantspain]

i have no idea on that but 1a for running sound, fan and rom drive seems awfully low

[penrhos]

He'd have a job - the standard PSU in a boardmaster is the same rating as the PANA - 7A on +5 and 1A on +12 & -5. I swapped mine out for a bigger PSU as I kept blowing fuses.

[Eddierang]

Penrhos, which PSU did you use on your boardmaster?

[Eddierang]

I don’t think my question got really answered, can I just swap out fuses for higher current fuses on each line or do I have to change power supply as well when I change the sizes of the fuses? Would like to not have to do any serious modding if I don’t have to.

[Eddierang]

Update: put another 1A fuse on the 12V fuse box holder. Tested SSF2, got sound and fan on board running again. At this moment I dare not try running system 256 on that power supply. So as you guys suggested, sanwa power supply is underpowered for System 256. Now if I’m going run system 256 through the Namco I/O what are my options here? Could go the option of buying an external Sun power supply but I need to come up with the connector piece that connects the power to the wall, and use my spare Sega Jamma I/O for controls (might save me a headache for kickharness doing it that way. Or buy myself a Capcom I/O. What are good replacement internal power supplies to look at if I were to go that route?

[grantspain]

what is the rating on the power supply of the 12v line?

[penrhos]

The two I had, one had a Sanwa SWN-7F the other a CS-070 both are rated at:-

+5V @ 10A
+12V @ 1A
-5V @ 1A

Personally I'd use a small PC power supply with an ATX-Naomi power adapter to run the 246/256 as it'll be cheaper than a SUN PSU and 100V stepdown to run it. That way the BM is "Stock".

There is enough space to install a bigger PSU inside the BM but finding one that'll fit and where the +5V adjuster pot lines up with the hole in the back will be a problem - one I'm working on at the moment as my PSU was 100V only and the PSU I swapped to I can't adjust the +5V as the pot is in the wrong place.

[Eddierang]

I would like a have an ATX to Naomi power supply cable made for me if possible. Willing to pay for it.

[Eddierang]

Update, finally got this up and running, yay . I’m using a Naomi Sanwa Power Supply to do it. I did buy the JVS to ATX power cable and used a PC power supply that I wasn’t using and it seemed like it didn’t want to stay on. Not sure if it because I need to get another switch to rig it up or what since it’s not being connected to a PC motherboard.

[Ploppers]

Update, finally got this up and running, yay . I’m using a Naomi Sanwa Power Supply to do it. I did buy the JVS to ATX power cable and used a PC power supply that I wasn’t using and it seemed like it didn’t want to stay on. Not sure if it because I need to get another switch to rig it up or what since it’s not being connected to a PC motherboard.

Had this same problem when building my supergun with a PicoPSU;

For the ATX PSU you need to jumper the ON pins;

https://www.overclockersclub.com/guides ... in%20%2314.