No RPM's with 7 Volts Mod

[Kukkor]

After lowering the voltage of my pcToys Tornado MAXX (same as 80mm Vantek Tornado) to 7 volts, I don't get any RPM readings in SpeedFan or MBMonitor. Before it was running at 5 volts with no problems except for slightly high temps (48/51c).

This beast is mounted an a Dr.Thermal Copper Core TI-V77 CPU Cooler and I could not stand on the noise any longer. The 7 volts mod is temporary until I buy a fan controller or build some kind of rheostat that I can crank up the power when needed.

But I am concerned about the inability to read the RPM's at 7 volts. Any help is welcome. Thanks.


Note: The single RPM wire comes separate from the molex connectors and is attached to the MB CPU fan header.

 

[cheapgoose]

i had the same fan, same situation. rpm monitoring is not going to work period, i tried bios and also MBM5.

 

[Zepper]

The speed sensor pulse is read between the sensor lead and Ground! Your fan is NOT connected to Ground anymore. Capisce?
.bh.
:moon:

 

[Kukkor]

Got it. Thanks guys.

I hooked a SPDT switch for 5 and 12 volts and it's working fine. I get the benefit of a silent pc and when needed the full cooling power.
At 5 volts I can get RPM readings of 2637 and at 12 volts 6027.