That AMS 1085CM regulator is the adjustable version since it has no suffix - there's also R8 and R9 making up a resistor divider pair that set the operating voltage. Let's leave that for now and look at other factors.
Please do test with the PC speaker hooked up to see if it gives beeps or not.
On my 2 functional banshee cards the core voltage is ~3.5v in operation so it should be around there really and not 1.5v. Make sure that you're measuring the correct points - I think the AMS1085CM's power input is the 5v line and since it outputs 3.5v normally perhaps your measurement was between the Vout and Vin pins rather than Vout and GND/Adjust. Measure between the tab and the leg that connects to R8/R9, that should be Vout and GND respectively.
What motherboard are you testing the card in?