I know they made this system first, for about a year or less. Did any early models actually have the fan installed? I have number 40040238, it's possibly unit 40238, or unit 238.... It is a dev unit (grey) with blue buttons.
I was unaware of this (then again I've never held an old grey model). http://forums.sega.com/showthread.php?327150-Sega-Saturn-Early-model-had-a-fan has a picture of these holes if you scroll down a bit. Looks like someone was wondering the same thing but never came to any conclusion, unfortunately.
I wonder if it's possible to install a fan? I remember opening one of mine and I saw "FAN" printed on the board and there were posts where it would've attached to. I think there were even solder points.
As druid said, no Saturn's ever had a fan. My Saturn also has the vents and what's cool about the very first models is that they had 2 LEDs for the power and Access lights. This looks much nicer than the 1 LED each that Sega changed to. Also the font used on the access and power text is better IMO. Looks more mature.
I wasn't aware that they had changed fonts... can you post pictures comparing the two fonts if you can? I'm really curious...
Most likely SMD on both items. Might can get away with figuring out what is needed based on the supply voltage and the specifications of the fan used. I believe the Saturns are strictly 5V. I know my model 2 NTSC unit is.
