5V unsatble on Naomi Sun Power Supply Unit Model 400-5443

[nonosto]

Hello

I have 5V unsatble on Naomi Sun Power Supply Unit Model 400-5443. I already instal a new capkit and new Noctua fan. So Each boot of my cab I have never same value about 5v, with a range [4.6,5.4]. Do you have any alternative, with ATX power PC PSU ? I never seen one with 5V adjustable.

THX

 

[rolins]

Do you get the same unstable voltages when you plug in a different game?

 

[nonosto]

no, change sometime with games. I can have 4.8V with one game and 5V with other.

 

[rolins]

no, change sometime with games. I can have 4.8V with one game and 5V with other.

Sounds pretty normal to me. If the game runs normal at 4.8V you don't need to make any adjustments to the 5V pot.
You just don't want the voltage at the game pcb side to be over 5.1V

However the game you measured at 5.4V, can your PSU be adjust it down to 5V?

 

[nonosto]

yes I can adjust anytime with the 5v pot on PSU.
So what's the range for no damage, it's seems too low is as well too high.

 

[ekorz]

A PCB’s components want 5.0v for best performance. Even if a game happens to run lower or higher, you’re putting unnecessary stress on its components by under or overpowering them. They’re built with tolerance but will die faster if used that way. 5.0v at the chips, not 5.1 not 4.9. It’s not practical to measure at the chip, or to measure each chip, so pretty much everyone measures at the jamma edge. There is some voltage drop off from the edge to any chip, so most dial the jamma edge to 5.05v or something like that.

All games pull a different amount of current and most arcade PSUs don’t auto-adjust the voltage to compensate. It’s normal to have to adjust the voltage with a new pcb.

Just plug it in, measure, and dial it to 5v every time you switch games. If it’s fluctuating at that point, then it’s time to worry!