Discussion in 'Sega Dreamcast Development and Research' started by Nopileus, Jul 19, 2015.
Definitely interesting, also hate the noise mine makes. Will closely follow this thread, hopefully there will be a solution to this problem.
Can this be dome on a VA0 Motherboard?
Not yet, it will take a much different design to be able to replace the VA0 fan with a bigger and quieter one. I have a mostly functional duct designed for it, the issue I'm running into is space. There just isn't enough room for a 40mm fan, so I've started to look for another option.
I have some mixed parts
VA1 Motherboard and case, but i have VA0 Heatsink. Can i use that heatsink or shall i remove that and add some heatsink parts?
VA1 motherboards don't need the heatpipe heatsink, they work just fine with the aluminum plate on the metal rf shielding, the fan mount in this thread works just fine with the VA1 shells and you can fit the bigger quieter fan in the system. The system relies on checking if the fan is spinning to determine if there is a chance of a thermal issue. So you need a fan that can tell the system it's speed.
The VA0 motherboard does require the heat piped heatsink, and it's speciality fan. The heatpipe has a thermistor mounted to it that shut off the system in the event of a thermal problem. I'm trying to find a small blower fan to use with the duct I made.
I understand that, shall i just add some aluminium on the ounderside of the shielding and dont use the heatsink? I also need an va1 controllerport.
Curious to know what you come up with. I rock a VA0 as well. The stock fan just sits so close the grill on the outer case. I always thought it would be cool to have a pusher fan on the opposite side.
No fan Check for VA1
Alternatively, here's another way to bypass FAN check (just wire pin 16 of IC305 to L301):
Do i need the resistor if i use an 5v noctua fan?
Yes unless you do one of the mods in the previous two posts.
But i have an VA1 board i tought the resistor turned down the faan speed?
We were using the resistor to override the fan check. The tach signal from the original fan is different from what the Noctua outputs, so if you just hooked it up the Dreamcast wouldn't boot. If you put the resistor across the 5v and tach signals the Dreamcast ignores the fan tach signal and boots.
I think it uses the signal from the fan, instead of blindly bypassing it.
I'll confirm this tonight, I thought it booted without a fan but maybe I'm remembering wrong. It's possible it steps up the tach signal to what the Dreamcast is looking for.
I have the noctua fan, im going to hardwire it but wich pins go where? on DC pcb it says 1 2 3 and i have yellow, red, black from my noctua. thanks
The center is ground, 5v is the pin closest to the front of the system, Tach is the pin closest to the GDRom.
Do you mean on the dreamcast or on the fan?
On the Dreamcast, the fan is wired
Red - 5v
Black - ground
Yellow - tach
There is a diagram in the first post if you want a visual
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