The current draw should be somewhere between 80 and 100 mA. The exact value is very much dependent upon the Si570, the version (CMOS vs LVDS), the frequency setting, and component variations in the circuit. You can test the SW1 programming of U3 by checking the dc voltages at pins 1 thru 7. Pins 1 thru 3 should always be approximately 3. 27 Vdc. Vo
ltages at pins 4 thru 7 will vary, depending upon their corresponding dip switch settings (pins 4 thru 7 correspond to dip switches 1 thru 4):.