The Issue
My Naomi system arrived ready for some gaming. I plug everything in, and instead of seeing a nice white Naomi startup picture I hear the noise of the fan spinning up and down like it’s not receiving the correct voltage. After doing some research I discovered others with similar issues. This main issues are:
- Unstable 12V due to high AC voltage talked about on Arcade-Otaku.
- If the Wei-Ya power supply input is not 100v exactly there appears to be problem. Read on Arcade-Otaku. Apparently anything greater than 105v AC will cause issues.
AWSD Information
First step was to take a look at the manual to see what the power ratings.
| 定格電圧 | Rated Power: AC100v 50/60Hz |
| 規格消費電力 | Power Consumption: 140w |
| 最大電流 | Maximum Current: 2.0A |
Two switching power supply models are found in original AWSD cabinets.
- AAA-01A
- P271
P271 pictures below.
The Options
There may be more, however the two options recommended where a new PSU or transformer.
- The Sanwa SWN-JVS power supply retails for 20,250 yen from Tops-Game in Japan.
- A 100v step down transformer.
I decided to purchase a 500w step down transformer (240v to 100v). I contacted the seller who said the transformer won’t output more than 102v AC. The transformer will provides a continuous output of 400 watts. The 300w transformer he supplies only outputs 200 watts of continuous power which would give me 60 watts to use with other Japanese consoles. I found these power ratings however I have not verified the accuracy.
- Dreamcast: 75 Watts
- PS2: 100 Watts
- Gamecube: 120 Watts
- Xbox: 150 Watts
- Xbox 360: 300 Watts
Testing
I have 3 contenders for the testing. Each one is a 110v stem down transformer, including the one supplied with my cabinet. First I decided to measure the voltages coming from the N1 connection on the JVS harness. All voltages were stable.
| 2000w | 300w | Original |
Output Voltage: 114.2v |
Output Voltage: 124v(L) 248v(R) |
Output Voltage: (not accurate) |
After plugging in the 2000w power supply my Naomi and CPS games worked without a problem. I definitely thought all of them would fail due to the output voltage. The 300w power supply had 248v running through it when I measured the right hand contact inside the unit, with the left side being as 124v. The holes in the original transformer were to small for me to get an accurate reading.
500w Step Down Transformer Testing
The new transformer arrived and my Naomi and CPS2 boards powered on without a problem.
Output Voltage: 103.7v to 104.5v |
Helpful Sites
Other helpful sites used to write this post.
Mondaiji's Arcade 