Dreamcast Fan Mod

[MAXIMUSpowers]

Ok heres my issue. I want to replace the fan in the DC as its too noisey! Should I replace it with a 30mm fan (same size as original) or a 40mm fan. Im not sure how the size will effect the noise but i have a feeling that the smaller one may be louder.

Im also considering adding a variable resister to it so I can alter the speed,

What do you guys think?

[BlueCrab]

Keep in mind the Dreamcast's fan (on most consoles I've seen anyway) has a 3rd pin that most fans you'll find don't have, which I believe is used by the hardware to detect the fan (maybe its speed, I don't really know).

Its not so simple as just replacing the fan, most likely (and I've never noticed it being very loud myself).

[MAXIMUSpowers]

yeah the 3rd cable is for the fan speed - this is where id ad a rheostat to controll speed . Ive located some fans that have a 3rd cable. If not ill just make a pulse generator to emulate this.

[DCDayDreamer]

Ok heres my issue. I want to replace the fan in the DC as its too noisey! Should I replace it with a 30mm fan (same size as original) or a 40mm fan. Im not sure how the size will effect the noise but i have a feeling that the smaller one may be louder.
A 'noisy' fan is in a lot of cases down to the bearing supporting the drive, the bearing might be dry which causes friction between it and the fan drive shaft, the bearing might be worn which causes the fan to become unbalanced (with additional friction). Another cause can be an accumulation of dirt on the fan blades which again causes an imbalance of the fan itself.

Larger cooling fans are normally designed to rotate at a lower RPM, they can rotate slower but still move the same amount of air as a smaller fan rotating faster, the slower a fan rotates the quieter it is. If you rotate a larger fan at the same RPM as a smaller fan, the amount of air moved will increase but the audible volume of the air moving will also increase.

A Dreamcast fan has seven small blades, an accumulation of dust particles on these blades can be enough to make it become unbalanced, whilst the blades are designed to be almost like a knife-edge, an accumulation of dust particles can make the the blade 'thicker', which again can make the fan more 'noisy' whilst rotating.

An easy remedy would be to clean the Dreamcast fan blades of all accumulated particles.

A secondary remedy would be to apply a small amount of lubricant to the fan drive shaft (the stainless steel pin in the center of the fan).

You will need to remove the top cover of your Dreamcast to do either of the suggestions below to any great effect.

Use a small paint brush to clear the fan of all particles, then use an air canister to blow the dust away (or use your lungs). Use a small drop of light oil similar to shaver/hair clipper oil on the pin in the center of the fan that faces outwards, peel back the small identity sticker that sits in the center of the fan that faces inwards, apply a small drop of light oil on the pin in the center of the fan, replace sticker, replace Dreamcast top cover.

NOTE: although easier to obtain, shaver/hair clipper light oil is not the best lubricant for fan drive shafts (it works, but not for extensive periods), it's better to use a light PTFE grease which gives longer lasting results.

[-x-]

--------------------------------------------------------
#~ SH4_FAN_CONNECTOR ~#
--------------------------------------------------------


advantage
.can be useful in case the stock fan no longer works
.if you do overclocking
.well you know ...

========================================#
screwdriver
solder
pc fan connector
molex (optional)
gpu mem cooler (optional)
fan (size matter)
========================================#
http://img9.imageshack.us/img9/5463/shmq.jpg
---------------
----
3 | |--
2 | |--
1 | |--
----
------
|-----------
------

3 sensor
2 GND
1 VCC (5v) fan *0.9A max


*if current(fan) greater than 0.9 the system wont boot
this limitation is actualy from the power supply
#///////////////////////////////////

standard_connector pinout (PC)

----
sensor 3 | |--
VCC 2 | |--
GND 1 | |--
----

http://www.allpinouts.org/index.php/Motherboard_(CPU)_4_Pin_Fan
#////////////////////////////////////


for better coolling you can use 12V from POWER
and connect ONLY the sensor , to fool the system ;)

fan <= 0.9A
---------
|\ --- /|
| | | |
|- |/ --- \|
|
|
3 2 1 (PC)
|-|-|
| | |
| | |-------> to ground (power suplly) or molex
| |---------> to 12v (power suplly) or molex
|-----------> to SH4_FAN_CONNECTOR sensor

http://en.wikipedia.org/wiki/Molex
you can also add memory cooler on GD-drive side

noise level will depend on fan and speed

hope this help

[-x-]

hold it
i tried with 2 other mainboard but it didn't worked :(
http://img59.imageshack.us/img59/7325/fndg.jpg

i also made a mistake while reading the new fan spec which was 0.9 W (power)
you may need even less than 0.9W(not tested) depending on your board or close to 0.09 A (orginal fan spec).

its good to keep it somewhere, just in case.

sorry for the inconvenience