F4-210 Fans

[hubsy]

Both fans emmit a low rumbling noise.
Noise increases when set to 100%.
4 x SSD drives fitted. So not HD noise.
Are the fans required?
Can they be switched off?
If not, can they be replaced?

[crisisacting]

The fans are necessary as everything internal only has passive cooling on it, so the air flow is required to move it outwards.

The fans likely need to be re-lubricated if they are ball bearing based.

A TerraMaster representative will respond with instructions if the very latter is the situation.