Mount and copy files from 3TB drive - RN102

Water got onto my nas from the floor above, not submerged, and it won't boot with the disks in it. So, I'm trying to learn how to mount one of the RAID1 drives from another machine and copy my data off.

Current state:
- With the drives in place and nas powered on, the lights blink for ~5 seconds and then the nas powers off.
- If both drives are removed, the nas powers on and stays on, with the power button light blinking slowly.
- If a drive is then inserted, the nas spins up the drive for ~5 seconds and then the nas powers off.
- I've tried working with the Boot Menu (https://kb.netgear.com/22892/How-do-I-access-the-boot-menu-on-my-ReadyNAS-102-202-212-or-312) but can only do this with the drives removes, and from other posts, this seems useless as all the information is on the drives.
- I've gone through this post below and haven't had any success.
https://community.netgear.com/t5/New-ReadyNAS-Users-General/getting-files-and-folders-off-rn102-3TB/td-p/1923826
- I've also bought and tried a new power supply, since it got water on it also. There was a suggestion elsewhere that it may be going and booting with the drives puts is too much load.

Connecting the drive to my Ubuntu 22.04 laptop with SATA to UAT connectors, it appears the WD30EZRX 3TB drive is only reporting as 746.5 GiB. I tried Western Digital disk tools on it from a Windows machine, but they won't recognize the drive. Windows Disk Manager sees the drive and partitions, but I didn't go any further with it from there.

GParted show this and the only menu option is to delete it.

GDisk original output:
GPT fdisk (gdisk) version 1.0.8

Warning! Disk size is smaller than the main header indicates! Loading
secondary header from the last sector of the disk! You should use 'v' to
verify disk integrity, and perhaps options on the experts' menu to repair
the disk.
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: damaged

****************************************************************************
Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
verification and recovery are STRONGLY recommended.
****************************************************************************
Disk /dev/sdb: 1565565872 sectors, 746.5 GiB
Model: EZRX-00D8PB0
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): 770C75B9-CCAC-4876-A6F3-925EB85A1134
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 5860533134
Partitions will be aligned on 64-sector boundaries
Total free space is 4092 sectors (2.0 MiB)

Number Start (sector) End (sector) Size Code Name
1 64 8388671 4.0 GiB FD00
2 8388672 9437247 512.0 MiB FD00
3 9437248 5860529072 2.7 TiB FD00

All I want to do it try and get to the 2.7 TiB partition and copy everything off to another USB drive. Any suggestions?

Thanks!