The only way ahead that I can see is to hook the drives up to a machine with exactly the same raid hardware and software. In other words, get a new psu for the Dell.
As you've been correctly informed, half your data is one one hdd, and half on the other.
For the future you could consider adding another pair of drives in a raid 0/1 array. This gives you speed and backup.
If one drive fails, you can get the software to 'rebuild' the array with no risk of data loss.
That is what I used to do. Worked well until the main board died. Had almost everything backed up, but to get what wasn't, I had to buy a clone board from eBay. Because only the same raid hard/soft will work.
It's also true that raid can still be corrupted. Virus/lightning/sheer bad luck.
I now back up to one of three externals. I have one, daughter has one and son has another. We swap drives whenever we meet.