If current-sense resistor R7 goes open, this is usually because it's a fusible/flameproof part that got overloaded from a mosfet shorting out. It damages the IC and new mosfet if you are not careful to check those parts too.
A dim light-bulb tester to power this is also a good idea to save on fuses and smoke. Even a 25W lamp is all you need to power it up with no load.