[USR-TC] 70A vs 130A PSUs.

On one of my USR chassis, I had 2 70A PSUs. One of them died. The only replacement I could find were 130A PSUs, so I bought two of them, and put them both in. Completely removing the 1 70A PSU. That night, the chassis died on me for half an hour. (something it's *never* done in its entire existence.) Did I get stuck with bad cards, or am I tool, and are they not interchangeable?