You can try minimizing the other hardware to lower the demand and see if it resolves the error, while the A100 80g is installed. If you can take it to the servers minimum to post (shown below) with the A100 80G installed, and still see the error, then you will likely need the upgraded power supply or replacing the card with the Version 2 (part number 575TK).   R7525 minimum to post is removing everything but the following;  
 Hi, I am having a problem on installing the A100 GPU(80GB) into the server, it is installed through the PCIe slot, it fits perfectly. But when I'm booting the system, it shows me the power issue.   1) R7525 with A100 40GB,  (Run without a problem) 2) R7525 with A100 80GB, which is connected using the DPHJ8 (Power Issue)   [IMAGE]  
Dell R7525 Power issue when installing A100GPU