X61 and its super loud, pointless secondary fan

[wujstefan]

Hello lads,

I'm back on feet and back working on thinkpad stable I have here. X61 got the shot now.

I was lucky to get a T9300 unit with one of the latest production dates.
Runs and feels fantastic, HOWEVER it has the secondary fan under the palmrest that does nothing else just mixes the air inside - guess this was for wireless cooling. Thingy is, when it spins of, the system is EXTREMELY loud. I cannot take this particular fan out - the system produces a fan error, and TPfancontrol just spins both fans at presumably same speeds, resulting in huge amount of noise.

Other than that, when tpfancontrol is installed, the system won't turn off itself at all

Is there any known way to remove the fan and prevent the system from checking its presence?

[dr_st]

Presumably - do something with the fan connector on the board, but I am not the person who knows what exactly.

[wujstefan]

I don't think it would help, really :/

This particular fan is controlled by eeprom U99. It seems to share the control but... with a different tachometer? If one of those fan stops, I will get a fan error. If I try to control any of them, I control both just the same way. Duh. I _THINK_ I have seen a piece of hardware using NE555 pulse generator, but creating such PCB myself is out of my skill range

[mikemex]

You could remove the fins from the fan and just leave the core. It'll still spin but make far less noise.

[axur-delmeria]

Anyone tried a jumper wire from the main fan's RPM sense pin to the corresponding pin on the 2nd fan?

[tecmes]

In following with my observations here... (viewtopic.php?f=30&t=134333)
I don't know how hotter than a L-series a T9300 runs, but a roundabout solution is to make sure your primary fan and sink are clean... You CPU should be the hottest component around, esp. with a secondary fan, and it shouldn't run hard all the time at all. The fact that it does seems suspicious to me and this may solve both issues at once...

[RealBlackStuff]

You've probably seen these, but just in case:
https://thinkpads.com/forum/viewtopic.php?f=30&t=114084
https://thinkpads.com/forum/viewtopic.php?f=30&t=113072
https://www.thinkwiki.org/wiki/How_to_control_fan_speed ==>> scroll to: Hardware specs
https://www.mail-archive.com/search?l=i ... newest&f=1