Precision 3930 disconnect fans?

Hello Community,

this 1U rack station has 3 cooling areas PSU, CPU and GPU, in my case it is 8 fans total.

Since I am not connecting any card to the PCIe nor have any disk in the righthand bay, I find 3 fans in this area not obligatory. They produce extra noise and waste power.

I have simply disconnected the plugs but the BIOS doesn't let start the system. Even the usual F1 override is not available. Is it simply overlooked by Dell? I see no danger in overheating since the rest can spin up a little faster whenever necessary.

Can you help me? Are there any options?