CPU fan problem - fan stops at low rpm Predator G3-710.

JakobKH

Hi,

I have a four year old Predator G3-710.

Around a year ago I noticed that the CPU fan would be idle (not spinning) when turning on the computer and once the CPU temperature rose above a certain (quite hot) point, the fan would start up and spin at around max rmp (4500), until the CPU had cooled down. The fan would then remain spinning at around 1200 rpm for some time and eventually stop. This process would then repeat.

I found out that if I engaged the CPU in computations, so it was kept from not getting "too cold", the fan would keep spinning.

Lately, however, I have noticed that I need to engage the CPU in more computations than before to prevent the fan from stopping. Before it was able to spin happily around 1200-1500 rpm and keep spinning. Now I need to keep it at around 2300-2500 rpm if I don't want it to stop.

The fan still speeds up to 4500 RPM when it has been stopped for a while and the CPU temperature has risen.

I have made sure that the cabinet and the fan and heatsink are free from dust. I have also removed the fan and taken a look at it from the underside, but couldn't find any dust etc.

My question is:

Could the fan be stopping because it's getting old and needs replacing?
To me, it seems like the power supply is ok (otherwise the fan wouldn't be able to speed up to 4500 RPM), but perhaps there is too much internal friction in the fan to keep it spinning at low RPMs, so only the boost to 4500 RPM kicks it running?

I am no expert, however, and would appreciate any thoughts!

JakobKH

I seem to have solved the problem.
It seems that the G3-710 fan gets worn down in the sense that after some time it cannot spin at low RPM. The G3-710 fan should always spin, but when it gets worn down, it cannot spin at the about 1000 RPM it normally would. In stead it's not spinning at all, and only when the CPU gets really warm (around 90-100 degrees Celcius) it spins up - probably because the bios then gives the fan full throttle which is enough to kick it and make it spin at around 4500 RPM.
Once the CPU has cooled down, the fan slows down, but because it is worn out, it doesn't just stay at 1000 RPM, but in stead it shuts down completely - until the next time the CPU is too hot.
I solved the problem by buying a replacement fan (same model as in the G3-710 - they are not produced anymore, but I found one on Ebay), and simply replacing only the fan, not the heatsink (the fan is held in place by four small screws).
Alternatively, you will have to replace the entire heatsink/fan with another model, I guess.

billsey

Yes, there are two ways that the fan can get into that mode. Either the bearings are wearing out or there's enough dust and muck to make it hard for it to spin. A new fan is likely the easiest solution. If you take the old fan and check it you should be able to feel if the issue is gunk (hard to turn, tight) or bearing (you can wiggle the fan sideways). That might help determine if the long term solution is to clean more often or to buy better quality (though you can always do both ).