Markbass Little Mark III Head - Cooling Fan Revs High and Low

[iPlay5]

Hey everyone,

I've got a Markbass Little Mark III and the cooling fan revs up full blast right when I power it on, then fluctuates down to low, then full blast again - it repeats that pattern the entire time it has power. The amp itself never gets hot.

I've looked inside and don't see anything obvious. I don't think the fan itself has any logic built into it, it seems the speed would be determined from some type of thermal sensor.

If anyone has any ideas, please feel free.

 

Thank you,

iPlay5

[yorks5stringer]

Having replaced a fan once on a 250watt version might it be worth disconnecting the fan, use some switch cleaner and reconnecting?  I think you are right ( from memory) that the fan is just a fan, these are basically just computer fans although I never managed to source one in the UK outside of the authorised repairer.

[Hellzero]

This fan is dead silent and is a direct replacement : https://www.amazon.co.uk/Noctua-NF-A6x25-FLX-Premium-Quiet/dp/B009LEKGGE/

[DGBass]

My LMIII is quiet from start up and even at full gig performance never seems to get very noisy fan wise. It's difficult to tell though when I'm running it into a 4 ohm load at high power and things be shakin' all around. If your fan rev's up to full speed at power on, I would suggest getting it checked out just incase there is something amiss. It may be a symptom of impending doom! 

[ebenezer]

My LM2 does the same after a lay up of 3-4 weeks but when used regularly IE weekly is ok.