Have you considered looking for a High Point PCI RAID card that uses the 370 controller?
While the BIOS will be different, the basic RAID topology will be the same.
I've got 2 systems with this exact same board, and 2 others with an older version. Both systems with the KT7A are showing signs of motherboard failure.
I bring this up because 6 years ago when these were new they were part of one of the rounds of bad capacitors.
It might be worth having a good repair shop replace all of the capacitors on your board and see if that brings it back to life.
Back when these were new, there were a couple of shops that offered a full cap replacement for around $60 (US).
Another option, would be to search Ebay for a used board.
A functional used board should get you up and running at least long enough to back up the array so that you could rebuild it on new hardware.
That is another factor to consider. Your drives are getting old and it is getting hard to find the small (130 GB Max) drives that the 370 controller supports.
Chas