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View Full Version : PowerMac G4 FW800 (MDD) Silencing thru fans replacment




Nameci
Jun 8, 2011, 09:02 PM
Hello Everyone,

So i have embarked on another project. This project aims to reduce the fan noise on the notorious PM G4 MDD "wind tunnel".

Recently, I have bought a pair of Vantec ThermoFlow TF6025. Opened up the G4, did some surgery on the Power Supply replacing the power supply which is very noisy and irritating. It runs all the time at full speed.

Replacement was pretty straight forward. On the Vantec Fans there are three wires, Red, Black and Yellow. Red and Black is for the power supply and yellow is for RPM detection to the motherboard. This Vantec fan has a temperature sensor so much so that it reads the temperature and would regulate the fan speed depending on the temperature of the object or space that it cools.

Connected the Red and Black Wire and left the yellow wire since there is nothing on the logic board that I can plug it in.

On start up there is not much pull from the fans I am guessing that the temperature is still low therefore the fans are turning at lower rpm, am I correct?

Previously, I am hearing a low pitch noise, now I am hearing a low pitch noise coming from CPU fan.

I think my next project would be to replace the CPU fan, at least I can have a little quieter MDD.



666sheep
Jun 9, 2011, 01:45 AM
I am guessing that the temperature is still low therefore the fans are turning at lower rpm, am I correct?


Not exactly. Lower rpm = lower efficiency. To pull as much air as original fans (~25 CFM), new fans should run @4200 rpm (full). So IMHO temps are higher now.
This also depends on what fans you've had before. IIRC, there were at least 2 kind of fans in MDD PSUs. Minbea ~25 CFM and Delta ~35 CFM.

Nameci
Jun 9, 2011, 05:45 AM
The ones that I have pulled out was delta, and they are really noisy. Delta's supposed to pull 38 cfm each am I right? Do you know of a specific match but of lower dB rating compared to the Delta's?

666sheep
Jun 9, 2011, 03:44 PM
The ones that I have pulled out was delta, and they are really noisy. Delta's supposed to pull 38 cfm each am I right? Do you know of a specific match but of lower dB rating compared to the Delta's?

I know only 2 +/- as efficient as Delta :

- Everflow 126025 DH (32 CFM, 31 dB) - discontinued AFAIK, aftermarket only - they were used in Thermaltake Volcano 5 & 6 CPU coolers -> ebay

- Sinwan SD6025PT-12H (HH) (32 CFM, 32 dB) - IDK where to buy one...

"DH" and "HH" are important. There are almost identically coded fans, but with different specs.

JoeG4
Jun 10, 2011, 06:58 AM
Bleh. That reminds me of the time I ended up buying an akasa fan from England for my QS G4 (made in China!) and the fan conked out about a year after. >> Ended up replacing that with a random antec that happened to have even better efficiency. :D

The real pain in the arse with these G4s is the stupid 60mm fans :O