4d Gen 2 uncertainty

I have a 2nd Gen 4D with 4 2TB drives that (after 2 years being turned off) won’t mount yet I still need to retrieve my files. There are 3 green lights and 1 yellow but there doesn’t appear to be any failed drives just a system thats 85% full. There is feedback that suggests I replace slot 1 with a larger drive but I don’t want to put any more money into a dead end system. Will replacing this suddenly allow the system to mount and work well? Will this old architecture support such large drives? I believe when I bought this system, it was at a time when 1 TB drives were the largest available. Would the better investment be to migrate these 4 drives to newer drobo architecture?

The gen-2 machines will handle larger drives as long as the firmware is current (version 1.4.2.) I’ve tested 8 TB drives in mine with no issues.

Make sure your USB cable is fully seated on both ends. You could even try another cable if one is handy.