Let's double-check the ribbon-cable connection. With that in place, take a voltage reading at the breakout's VCC pin. It should be 3.3v, obviously. Thing is, it's possible to connect the ribbon cable to the RasPi's GPIO header in a way that sends the signals to the wrong pins.
Also try `sudo i2cdetect -y 0`, just to see if anything shows up on the other I2C bus. There are some version issues there, too.
When you void a product warranty, you give up your right to sue the manufacturer if something goes wrong and accept full responsibility for whatever happens next. And then you truly own the product.