Could a missing blade of a fan result in hardware failure

Question

I'm using an example that I have just encountered, but it involves a more general question regarding computer hardware and airflow.

For some reason my NVIDIA 9800 GT fried, I've actually no idea why. Upon inspection, it appears that one of the blades of the fan has snapped off; absolutely no idea why :s (that's 1/11 of the blades). I don't actually care that it's fried, it's quite old, however, could this missing blade have actually resulted in the card frying?

Anyway, it got me thinking, given different sets of fans, with different blade counts, how much affect on the cooling ability will losing a blade have? I.e. how much will the suction be affected?

Solution 1

Losing a fan blade on it's own for the amount of pressure loss that you get isn't really the issue. The issue is that if you've lost a fan blade the fan is now not balanced. An unbalanced fan will spin much-much slower than a balanced one, and that is what would result in much less airflow/pressure.

If it's an old card, then it likely did not have over-heating mechanisms to help it cool down or it could have just run hot for a long time resulting in faster degredation of the silicon. In any case, yes a fan that is missing a fan blade will result in pre-mature failure.

Solution 2

If a fan failed to start , I can see good reason for GPU failure, but not just for a small reduction in flow.

Fan failure here could have been a screw driver or cable interfering during operation.

No spin on start can fail then a push to turn gets it working again such as with a screwdriver. These dead zones are common due to misalignment of the Hall Sensor where max torque is right next to "no torque" and process variation can cause epidemic issues perhaps on only 1 of 4 or 8 stop positions controlled by magnets. It can also be degraded by change in magnetic strength with hysteresis. But this assumes, your fan had this problem on 1 of 4 or 8 random starts and it didn't start bad until aging effects on Hall Effect commutation.

Solution 3

Well, the blade missing itself may not have cause the card to die, but since the blade broke off and prob. jammed the rest of the blades from spinning at all, I can see that as being a reason for the card getting too hot and leading to failure and death. If I stop one of my case fans, it will pulse a little with positive pressure in the spinning direction.

Comments

[daraos]

I see this question has been migrated from Electronics, but I think it belongs to Physics. What effect one blade has on air flow depends on rotation speed, torque, size, angle, and total amount of blades, and probably some other factors. But as I said, this is not the Physics Exchange...

[Mark Ramotowski]

So if i snap another one off on the opposite side, this would be better than doing nothing at all?

[Fikri Hailal]

The number of blades is usually uneven, so there are 2 blades on the other side of the missing one. Snapping one off is not a good idea IMO.

[horta]

If they're even yes, snapping the opposite one off would be better. If they're not even, then you're just SOL.