The diodes are a

The diodes are a safety option to make sure the fan will speed up to 100% in case of overheating no matter any lower manual setting or driver crash. However some cards have been equipped with a bad diode that heats up due to an unwanted leak current. Because of that it speeds up the fan as it wrongly supposes the gpu to be overheating. The faulty diodes have been used in various batches so there is no way to find out what card is equipped with a faulty diode until the customer issues rma.

The problem can be solved by removing the diode. No matter if you already removed the diode or it is still in place the cards can be rma'ed. MSI already adviced the service centers on how to replace the diode with a working one. With just the diode removed the card will work fine but the safety is dysfunctional.